Some days are just destined to be unpleasant. This was one of those days and Enchanted Rose knew it better than anypony. She woke up much later than she should have. Her lessons went poorly, which was new for the small unicorn. Not only did she fall asleep during her magical theory lecture, she had been caught snoring of all things. It wasn't her fault she needed to identify the different types of meteors from the shower the previous night. The only thing that could possibly brighten her day was her evening lessons. It still took some getting used to, but it was nice to have the princess all to herself.
After the long trek up the stairs of Princess Luna's tower, Rose let out a happy sigh. Smiling at the house guards posted on either side of the door, she knocked and entered the princess's apartment. Princess Luna smiled at the sight of her student before looking at the time and frowning. "Rose, you're a few minutes earlier than usual. Are you having a bad day?"
Sighing, Rose set down her saddle bags and took a sat across from the princess. "Princess, you know me so frighteningly well. To answer your question, yes, I am. It's just one of those days." She looked up wearily before doing a double take. Was that guard there a minute ago? The light blue pegasus stood silently at attention, her cobalt armor signifying that she was one of Luna's guards. Her turquoise and blue striped mane fell out of her helmet a little as she saluted. "Is this a new recruit?" Rose asked. She certainly hadn't seen this guard before.
"Enchanted Rose, this is private Songbird. She will be your personal guard until further notice," the princess said. "You've found yourself in a few too many dangerous situations the past month, and my sister and I thought it best that somepony be assigned to protect you." When she finished speaking, all Rose could do was sputter.
"A GUARD? I don't need a guard. I've only been in two dangerous situations recently, and I assure you that I handled both perfectly fine," she said after composing herself. As much as she hated arguing with the princess, Rose felt that her response was well justified. Just because some random stallion tried to mug her in an alleyway, it doesn't mean she can't take care of herself. Princess Luna had to convince Rose to turn him back to a pony after it was over. She thought he had been a rather cute lizard. "I don't see any reason why I should need one."
Princess Luna set down the quill she had been writing with on the desk before rubbing her eyes with a hoof. It was still relatively early for her as she hadn't had breakfast yet. With a deep sigh, she said "My dear Rose, I know full well that you are capable of handling potentially hazardous settings, but I cannot simply let you go around turning ponies into lizards. And I certainly can't let you keep said lizard/pony as a pet. It's a matter of putting my mind at ease. You are a very talented and gifted young mare and could no doubt become even stronger and well versed in spells in time, yet such a time has not come. This is merely a precaution."
Rose was beaten and she knew it. "Yes, princess," she said. They started her lessons as she was resigned to her fate.
"Must you stand so close?"
Songbird stayed silent. It wasn't worth. Three years of guard training was paying off.
"Seriously though. It's kind of weird having somepony follow me around all the time."
Stone faced.
"How long have you been in the guard?"
No reaction. She didn't have to interact with this prissy unicorn, just make sure she didn't get killed.
"I plan on blowing up the base of Canterlot Castle."
Really?
"You're no fun."
This was going to tough.
Author's Note
Woo hoo! My first story! The idea for this came when my friend showed me a few of her OC's. They're both so cute and I couldn't resist. Currently, there is no proofreader or editor. If someone could help me out with that, that'd be great. 
Songbird and Rose fell into a simple routine after a few days together. Songbird arrived at Rose's dorm approximately ten minutes before her first class of the day. Rose would then complain about how early it was, while begrudgingly getting the books she needed. They would go to class while Songbird stood right inside the doorway to assess any possible threats. All of Rose's morning classes went like this until they had a break for lunch. After lunch, Rose had free time to study or leave campus.
During lunch of their fourth day, an especially confrontational unicorn tried to pick a fight with Rose.
The day was nice. The weather ponies sure have outdone themselves today thought Rose as she looked at the familiar surroundings. The courtyard students and school faculty used for meals was bathed in sunlight. Ponies were already coming out from the secondary school building. The green turf felt soft beneath Rose's hooves as she trotted over to her usual spot in the corner, Songbird following close behind. She sat, enjoying the rustle of leaves and soft chatter of ponies while she opened the latest Daring Do novel.
A hoof slamming on the table tore Rose's attention away from her book. She sighed while marking her place. Glancing at her guard, she wondered why Songbird didn't tell her somepony was coming towards them. Only then did she notice somepony had magicked her wings to her side and her mouth closed. Rude.
"Honestly, you'd think somepony could get some peace around here," grumbled Rose. The mass of yellow and green fur with a horn, appropriately named Lemon Tart, practically growled. "I knew you were dimwitted, but I didn't realize you were dumb enough to attack one of Luna's house guards."
"You keep your smart mouth shut, if you knew what was good for you," said Lemon. "Just 'cause you're Princess Luna's student, you think you can do whatever you want, and that includes cheating off my test in charms class," she finished.
Rose rolled her eyes with so much sass, she could've killed an alicorn. "And why, pray tell, would I cheat off of you? It's not like you have particularly good grades," Rose stated bluntly. "What good would it do to bring down my near perfect grades?" She sat back down, considering the spat over. That wasn't a good idea. Faster than she could react, Lemon's hoof came up to her side and knocked her off the bench she had been sitting on.
Going with the momentum, Rose rolled onto the grass before springing back up and striking a defiant pose. "Wow, Lemon. It's like you want to be expelled." Everypony in the courtyard fell silent at this point. Fights were rare, and most ended in one of the princesses having to break it up. "Do you enjoy torturing smaller students? Of course, you should know this pretty pony packs a pretty hard punch," Rose taunted while nonchalantly inspecting her hoof.
Songbird was furious. The blue of her coat was turning purple with red hot anger coursing through her veins. All she could do was make grunting noises and hope Rose noticed. Not that she notices anything but herself she thought bitterly.
"Please release my guard."
Lemon scowled at that. "Why should I, pip squeak? What are you gonna do if I don't?"
Letting out an irritated sigh, Rose lit up her horn. A large yellow blur went soaring into the air, accompanied with a high pitched squeal. Lemon's grip on Songbird fell away as she went higher and higher. "Huh. I didn't think I could get her that high."
"Rose!" barked Songbird. "You can't just throw ponies into the sky when they don't do what you want!"
"She had you pinned! What was I supposed to do?!"
"Call one of the princesses, a guard, somepony!"
"Oh, like a guard could do anything. You did a great job, by the way," Rose countered sarcastically. Lemon was still held in the air 30 feet above the ground.
Throwing Rose a dirty look, Songbird flew up to where Lemon was floating in an attempt to get her down. "Rose, let her go! You're going to get into more trouble if you don't!" she yelled down. A yelp escaped Lemon as Rose dropped her hold on her. Songbird caught the bulky unicorn and had a very choppy descent. "Geeze, if you keep thrashing around like this, I'm gonna drop you," she said.
Once they safely landed, Songbird turned around only to face Princess Celestia.
"Uh oh."