The Elemental Fillies

Princess Celestia was pacing around her room. Next to her there were a white alicorn filly with windy hair and pure gray eyes.

"Mom, where is Fire Shine? Or Water Shine? But Earth Shine?" the filly asked.

"I told you, Air Shine, they are forming inside their existence sources! Water Shine is in the ocean, Fire Shine is in a volcano and Earth Shine is in the rocks!" Princess Celestia replied.

"But I am not in my existence source. Why is that?" Air Shine said. "Am I special?"

"Look, I think we shouldn't talk about this right now."

"We shouldn't?! You said that you could tell me anything I want!"

"I did, but except the Elemental Fillies."

"Just tell me! You always have secrets! But why?"

Celestia sighed. She levitated a dusty book and dropped it in front of Air Shine.

"What's this?" the filly asked, curious.

"It's my... journal" Celestia replied.

"You have a journal?"

"Yes."

Air Shine stared at the book for a few seconds. It was a brown book with the Royal Sisters Flag on it.

"You and Auntie Luna both owned this?" she asked.

"Luna has a separate diary. I couldn't use my cutie mark as the cover picture because I had another book with it" Celestia explained.

"And what was that book about?" Air Shine wanted to know.

"I don't want to talk about it" the older alicorn strictly spoke.

Suddenly, a loud blast was heard. Celestia knew that Earth Shine fully formed. Then, the volcano where Fire Shine was in sprouted lava. The ocean formed a bubble and inside it resided Water Shine. The three elemental fillies fully formed. They were teleported to the balcony of the Canterlot Castle.

"But... It isn't possible..." Celestia whispered.

Fire Shine, the crimson pegasus with fire hair and light red eyes, went closer to Air Shine. Earth Shine, the brown earth pony with rocky hair and green eyes, approached Celestia. Water Shine, the dark blue unicorn with icy hair and light blue eyes, stood at the balcony, looking at the moon.

"Who are you two?" Fire Shine asked.

"Um, mom?" Air Shine asked. "Are they the other Elemental Fillies?"

"What are those 'Elemental Fillies'?" Earth Shine asked.

"You all are my daughters" Princess Celestia replied.

The four fillies' flanks began to glow. Their cutie marks appeared. Water Shine had a light blue water drop, Air Shine had a breeze with some small leaves, Fire Shine had a red flame and Earth Shine had a brown rock.

They were the Elemental Fillies.