Physical change was, apparently, quite normal when you were suddenly infused with ultra unholy ultimate power of the Gods.
In hindsight, Twilight should've seen this coming. At least, this was what Pinkie mused to herself as she watched the alicorn stumble about with the undignified (but admittedly rather endearing) grace of a newborn babe.
'Growth spurts' was the word that Twilight had grumbled at her, when Pinkie thought to finally ask why the alicorn's legs had become gangly over the last few weeks. Her legs had lengthened considerably, knees awkwardly propping out as her body became used to the adjustment, knobby features that reminded one of a filly going through puberty. Upon further inspection, Pinkie began to notice the other little changes - many of her features had become just the slightest elongated, similar to the body types of other alicorns. After questioning her concern, Twilight assured the earth pony that she was in no pain, to her utmost relief.
She brought a hoof to her mouth, contemplative. To the average pony, many alicorns had the semblance and air of giants. Being quite small herself, she had to crane her head back far to look Celestia and Luna in the eyes. Cadance was much easier, but who knows how big Twilight was going to eventually get?
"...What are you looking so serious for?"
Twilight's voice brought Pinkie out of her deep thoughts with a start, her mane and tail bunching outwards for a brief second. By the look of worry on the other's feature, it was clear that Pinkie's uncharacteristic silence was enough to gather her attention.
"Mmm..." Pinkie drew her hoof away from her mouth, only to place it on her cheek. "I was thinking about how if you grow even more, you're gonna have to bend down reeeeeal far to give me a smooch."
To her delight, Twilight responded by unintentionally flaring out the feathers in her wings, the fur around her chest fluffing up in unison. A reaction of embarrassment that was normally reserved for pegasi (naturally, Fluttershy was the one who most often did this). Seeing Twilight do this, spluttering and blushing and trying to smooth down the fur and feathers, made a pleasant warmth fill up in Pinkie's chest.
Once Twilight had made herself look more presentable (mostly was the key word, as many of her now feather-like pieces of fur were still crooked), she gave Pinkie a look, caught somewhere between fondness and annoyance. "Why don't you just bounce up, or float up, or do whatever nonsensical act of Pinkie Pie logic you can concoct, so I don't have to be bending my neck all the time?"
The grin on her face threatened to grow wide enough to hurt, enough that the side of her mouth felt strained. A few times Twilight - of all ponies! - had joked that if she continued to smile in such an exaggerated manner, her face would be permanently stuck that way.
Not that she would mind too much. She smiled so widely and so constantly around Twilight, it might as well be stuck that way!
With a giggle, Pinkie tilted her head, the tip of her hair bouncing jovially. "'All the time'? Do you plan on smooching me even when we're not in the same room? I don't think your neck's going to get long enough for that!"
Another pointed look, the fondness in it strengthening. "Well, I'm sure your neck will reach far enough. If I didn't know any better, I'd say you were made out of taffy."
This was a norm now, for the two of them. Where Twilight initially sceptic of the strange things Pinkie was capable of before, it now had become a mutual joke. The fact that the unic-alicorn had completely and totally accepted all of her partner's oddness made said partner feel all floaty inside.
And now, Pinkie was going to have to do the same for her. She was used to getting all stretchy and taffy-like, and the others were used to seeing her do so, but to see her girlfriend grow in such a sudden way was rather jarring. Naturally, she still loved Twilight dearly, but now she took up the majority of the bed! And sometimes Pinkie would wake up to knobby knees pressed sharply into her tummy.
Speaking of which - those knobby knees were starting to go again, as Twilight began to try to take another few steps. Two of which were successful, but at the third her hoof clumsily clipped against the stone of their bedroom floor. She was relieved of having an ungraceful face plant when Pinkie bumped up against her, keeping her upright.
When she was completely stilled, Twilight sighed and said, "You know, I never thought I'd have to experience what it's like to be an old mare this early on in my life."
"I don't know if I'd compare you to an old mare," Pinkie replied presently, easing Twilight over to the bed. "Have you seen Granny Smith? For an old lady she can really move!" She gave Twilight a cheeky smile. "You're more like how the Cake Twins were when they were born."
There was a pause.
"Didn't they have insanely skilled powers when they were born? Enough that they actually gave you a run for your money?" Twilight reminded her.
"...oh. Yeah." Another contemplative look. "Don't worry though! Princess Celestia and Luna said that you're going to adjust to this soon enough, just like how you adjusted to being able to fly!"
Twilight huffed. "At least with the wings I could still get around fine on my own hooves."
"True...but maybe now that you are used to them, you can just pull a Rainbow Dash and fly everywhere you go!"
The suggestion was met without a word, only a heave of a sigh from the alicorn. Twilight looked tired, with the slightest darkness under her eyes. Even though she wasn't hurting, the sudden changes in her body were obviously putting some form of stress on her.
Pinkie could feel the lilac feathers expanding against her, easing back only somewhat once the long suffering exhale was finished. She couldn't help but snuggle up closer, a pleased noise leaving her own muzzle. The smell of books, crisp pages and musty covers, filled her nose as Twilight leaned against her.
"Don't worry," Pinkie spoke up again, after a moment. "I helped my Mom and Dad deal with Marble when she was born, and she was super wobbly! I mean, you're a lot larger than her when she was born - a lot a lot larger - but I totally don't mind being your walking cane until you don't go tumbling after one step!"
Twilight snorted in response, a repressed laugh, and regarded Pinkie with another fond glance; no slight annoyance this time. The pleasant, airy feeling continued to fill Pinkie, until she felt like one of the balloons on her flank. "So when I have to go somewhere on Princess duty, you're going to be pressed up against me the whole time?"
"Yep!" came the immediate response, followed by an airy laugh. "I'm officially the Royal Walking Cane!"
Again Twilight snorted, a wry smile spreading over her snout. "I can only imagine the look on the Royal Sister's face's."
Pinkie could easily conjure up the image herself, of Princess Luna and Princess Celestia looking flabbergasted as Twilight held onto her akin to the way that elderly ponies held onto their walkers. She was unable to help the stream of giggles that left her soon after said image came to mind.
Her laughter was amongst the most contagious a pony could muster, so it wasn't much of a surprise when Twilight's own laughter, rich and beautiful, joined Pinkie's.
And that was all that needed to be said about that. Within time Twilight would grow completely accustomed to being an alicorn and be able to walk without assistance. But for now, Pinkie was utterly and totally satisfied with being the self proclaimed 'Royal Walking Cane'.
(And, by the way, Princess Luna and Princess Celestia's reactions were wonderfully amusing).
She was frazzled. And Pinkie was never -- no, not quite never -- was rarely frazzled, at least the sort of frazzled where your heart was thumping and all your nerves felt like they were all being electrocuted at once and you couldn't stop moving and being all fidgety and frazzled because when you're frazzled it was like never ending sugar rush of anxiety and Pinkie never got frazzled!
Frazzled was starting to not sound like a real word.
...was it even a real word? Twilight would know.
Regardless, she was fraz--nervous. But who wouldn't be? Anypony would be outright, stark terrified at the fact that their wife was giving birth to their child. And anypony would be outright, stark terrified if the pregnancy that came before the birth was riddled with problems.
Pregnancy between same-sex ponies was fortunate enough to have multiple options. They could have a surrogate, a donor for impregnation, or if they were fortunate enough to have a particularly powerful unicorn (or alicorn) around, they could either turn one of the mares into a male, or do some magic mumbo jumbo (as Pinkie eloquently put it) and kinda pop the beginning of an embryo in there.
The magical change from mare to stallion was what they chose, and although Pinkie found it quite fun being a male (even though Twilight was still taller than her!) the aftermath was not what she had expected.
The time from conception to birth was unbelievably long with ponies, and Twilight's body took a severe physical toll throughout the entire time. The aches, the exhaustion, the morning sickness that managed to cause concern with the local doctors, all made Pinkie's heart ache terribly for her wife. The only solace was that Twilight's mental health stayed phenomenally well, as the alicorn had become more and more emotionally stronger over the years they'd known each other.
Pinkie worried, and she never liked worrying as it made her hair deflate and her coat go a more murky pink, and she worried about the horrid possibility of losing the baby, or Twilight, or even both. In an ironic twist, it was usually Twilight comforting Pinkie about these sorts of things - while the pink mare returned the favour by aiding her with all of her physical problems.
But now, they were here. The end game, the home run, Twilight laying on the soft hospital bed as the nurses fussed over her, a healing magic being supplied to keep the pain minimal. She was somehow calm, so insanely calm, that Pinkie couldn't help but think back to all the times where her partner had breakdowns over worrying if something was going to turn out okay. Though she was matured, she still sometimes became a big ol worrywart...but here, she was almost serene.
Instead, Pinkie was now the big ol worrywart.
She brought one hoof up, stroking Twilight's hair idly. A light sheen of sweat had made itself present against the fur on her forehead, making it stick to her skin. Her breathing was level enough, only the slightest bit shallow.
Medical magic made this so much easier than it used to be. Pinkie couldn't even begin to imagine what it would be like if Twilight was screaming and there was blood everywhere and --
But that wasn't the case. In fact, when the birth - the nurses called it 'foaling' - actually happened, it was a little anticlimactic. It was simple and quick, though a little jarring to see Twilight just...produce all this goop. And there was a lot of goop. So much goop that Pinkie became alarmed when she saw it.
"U-uh, where's the baby?" she asked, her voice strained with worry. "Is that our baby? Did Twilight give birth to a smooze?"
In her defense, Pinkie was really frazzled.
The nurse - Nurse Redheart - gave a small chuckle, as she bundled the goop into a fresh blanket. "No dear, this is indeed your baby. We just need to clean her up and then you'll be able to hold her."
Her?
Pinkie's head spun, and she looked back to Twilight, who had been holding her hoof this whole time. She looked as awestruck as Pinkie felt. Technology was limited when it came to finding out the sex of the foal, so they had decided to wait to tell what it would be.
"It's a girl," Twilight said breathlessly. The look on her face was enough to make Pinkie's mane and tail expand with the most pure joy she had ever felt, the grin spreading over her features wide enough to crack her mouth, and she felt herself beginning to vibrate.
She would've exploded with the force of every confetti canon in the world if it weren't for Nurse Redheart bringing over their newly cleaned babe.
Their daughter - their daughter! - was bundled in a new blanket. She was handed to Twilight, and the first thing that Pinkie noticed was her hair, something that she couldn't help but comment on.
"...she has a afro."
The most noticeable feature was indeed the giant mass of pink curls placed on top of her head. Her eyes, small and also pink, peeked out from underneath.
Twilight stroked their daughter's curls lovingly, revealing a tiny horn in the middle of it. "You know, the first thing new parents usually say is 'they're perfect'."
"Well, she is!" Pinkie responded, moving closer to get a better view. The newborn unicorn blinked up at her, before proceeding to suckle on one of her tiny hooves. "And she has a perfect afro to boot."
Tentatively, as if afraid she would shatter under her hoof, Pinkie reached out and joined Twilight in stroking their little one's mane. It felt like her's, springy and a little like cotton candy.
"Do you have name ready for her yet?" their nurse asked gently, smiling at the trio from over her chart.
"Neither of us really discussed it," Twilight admitted, as she lightly nuzzled her nose against the lilac cheek of her daughter.
"Yeah, I guess we just figured that like every other pony in the world, at the birth we'd end up somehow naming then something that was going to be relevant to whatever passion or personality they were going to have in the future," Pinkie supplied, before pausing for a moment. "...has anypony ever thought about how weird that is?"
Nurse Redheart's face promptly morphed into an expression one takes when they find out their whole life is a lie.
"Ignore her," Twilight quickly interjected. She looked down at the bundle wrapped in her front legs, offering said bundle a soft coo. One tiny hoof, the one the baby was currently not suckling on, reached up to her. "We'll come up with a name for her soon enough."
For the time being, the new parents were allowed to rest, as Pinkie wormed her way onto the bed, wounding her short, pudgy legs around the long, elegant one's of her wife. There were several family members and friends waiting outside, horribly anxious to meet the newest member of their massive family, but for now, being able to have this quiet moment to soak in the fact that they were parents was needed.
Soon enough, Pinkie would pop out with the songs and the cakes, even though their little one was unable to eat such things as of yet, but this quiet moment was necessary.
In this moment she was at peace, and no longer frazzled.
Author's Note
I don't plan on doing a lot of drabbles surrounding the nextgen babs I made for everyone (unless you folks do like them), I couldn't help but do this one. c: The eldest TwiPie child was my first nextgen OC, so I have a large soft spot for her.
Their lil foal was eventually named Star Chamer. 
