Right in the library, Twilight's best friends were turned into.... fillies?
They were around the age of four, and they seemed old enough to attend school but still not old enough to speak properly. They were a bit younger than the CMC, and they of course still hadn't gotten their cutie marks (a filly gets her cutie mark around the age of six).
Twilight's eyes widened in both fear and shock. According to her math and her observations, Pinkie was three, Fluttershy and Rainbow Dash were four (Fluttershy being no more than three months older than Rainbow), Rarity was five-and-a-half, and Applejack was fully five years old.
Pinkie didn't look like the bubbly mare she once was, but rather like the old version of herself, when she still lived on the rock farm. Her fur was muted to a dull pink, her mane and tail were straight and also dully colored, and she seemed grumpy and depressed-ish, but Twilight herself didn't know if fillies that young could feel depression.
"T-Twilight," spluttered Spike, seeming at a loss for words. "W-What have you done?!"
Silence.
A moment passed, and that was when all chaos broke that silence, and loose.
Applejack's hat was too big for the small filly to wear, and she said in a high-pitched country drawl, "Ah'm still a big pony!"
Rarity was whining and bawling with a bite mark on her left front leg. "WAAAAH!" she bawled, tears flying all over the place. "She bit me!" With that, she pointed an accusing hoof at the grouchy Pinkamena, who was grumping in the corner as she said with a sassy spice to her voice, turning around to face Rarity, "So what?!"
"There has to be a counterspell for this!" said Twilight desperately as she had got up and flicked through the pages of her books as a young Fluttershy came over, tugged on Twilight's hoof, and said shyly yet cutely, "Um, Mama Twilight?.... I'm hungwy..."
"Well, you better find it quickly!" cried Spike as she was chasing a flying Rainbow Dash.
Twilight was extremely desperate to find a counterspell to get herself, Spike, and her friends out of this mess. But, none of her books seemed to have some sort of counterspell for age regression. It was hopeless.
Finally, Twilight had long last found the book where she had first found the spell, and figured it might contain a counterspell for the trouble she had caused. But she couldn't help but address Fluttershy, so she put the book out of her face and looked down at the young pegasus filly. "Sorry, Fluttershy," said the alicorn apologetically. "But I'm trying to look up a counterspell to turn you and our friends back into adult ponies."
Fluttershy looked up at Twilight sadly, her teal eyes swelling with hope. She made a whimpering noise a dog would make as a pouty frown descended on her face.
No, not the puppy dog eyes! They always work on me! thought Twilight as she looked down at the poor filly. After some moments of silence, Twilight groaned in despair. "Fine," she said annoyedly. "I'll make lunch."
Fluttershy grinned and trotted away.
Twilight looked back at the book she was still holding with her magical aura. Hmm, thought Twilight. I suppose it wouldn't hurt to let them stay as baby ponies for a little while....
I'll just cast the counterspell after I make lunch, thought Twilight as she put the book back on its shelf. "Alright, everypony," announced Twilight. "I'm making lunch for you all. Then, we'll have playtime. The dining room's downstairs."
Hardly anypony listened, and Rarity and Pinkie were fighting, Rainbow Dash was still teasing Spike by zooming around the room as the poor dragon desperately chased her around, and Applejack was fussing with her hat. Fluttershy was the only exception, who was already making her way downstairs.
Twilight, already getting frustrated with her young friends' disobedience, yelled, "EVERYPONY! We're going to the dining room to have lunch. It's downstairs! WHOEVER DOESN'T GO THERE WILL GET A TIMEOUT AND 15 MINUTES LESS OF PLAYTIME!"
Everybody immediately stopped what they were doing and looked at Twilight in shock. Even Fluttershy froze and curled up right on the staircase, whimpering. Then, they immediately and ashamedly walked downstairs to the dining room.
Twilight kept the menacing frown on her face, and once they had all disappeared downstairs, she sighed and relief as the frown was removed.
"Wow, well that was harsh," thought Spike as he wandered over to Twilight.
"Sorry, Spike," apologized the purple alicorn. "It's just that, well, I was getting frustrated with everypony disobeying me like that." Twilight sighed. "And I still can't believe I turned them into fillies..."
"It's okay, Twi," said Spike with a reassuring smile. "Maybe our friends will grow to like their new lives. And, besides, what's the worst that can happen?"
Twilight looked at Spike plainly with big purple eyes, before smiling in thanks. "Thank you, Spike. How hard can foalsitting five fillies be, anyway?"
That's when, all of a sudden, she raised her head in absolute shock. "Wait a minute... Spike? Do you remember when Fluttershy called me... 'Mama Twilight'?"
"Um, yeah..." said Spike, scratching the back of his head in confusion. "And?"
"Don't you see, Spike? Fluttershy called me 'Mama'! She called me her mom!" The princess gasped. "OMG. Spike, do you know what this means?!"
"Uh, no... What does this mean?" Spike crossed his arms and cocked an eyebrow, yet again.
"Well, what if the fillies think I'm like a motherly figure to them?"
"Well, you are twenty years older than them, Twi..."
"Well, I suppose it makes sense, considering on how I disciplined them. But, I want them to see me as their foalsitter. An older sister, if anything. It just doesn't feel right to be the mother of my own five best friends..."
Twilight crossed her left front leg with her right left leg, and a wave of silence crashed over the two.
Spike finally broke it and smiled a little. "Twilight, you're just nervous," said the dragon. "It's just a little spell. No big deal. I'm sure they'll turn back into the ponies we know and love soon."
As Spike walked toward the staircase that led to the dining room, he added, "Now, if you'll excuse me, I'm heading to the dining room to fix some lunch. You seem a bit exhausted."
"Aw, Spike," said Twilight, grateful that he volunteered to do that. "That's really sweet of you, but I'd rather fix them lunch myself. After all, it was me who cast the spell..."
Another awkward silence dawned upon them.
"C'mon, Twi," insisted Spike. "You already seemed tired with the job of taking care of five rambunctious fillies. I'd rather do it. Giving you the burden of having to take care of five little fillies and having to fix them lunch when I could just do it myself doesn't seem fair."
"Oh, Spike," said Twilight as she hugged Spike tightly before letting him go. "You're the best little dragon assistant I know. Now, go downstairs and make lunch, won't you? I'll be there in a short bit..."
At least 30 minutes later...
Twilight went downstairs to see what was going on. What she saw were five little fillies at the dining room, with plates and forks and knives and spoons and napkins that all were the respective theme color of the filly they belonged to.
Rainbow Dash was trying to hide under the long, white tablecloth, but when she saw the slightly stern look on Twilight's face she dashed to her chair.
Spike had already served them all fresh carrot-flavored soup topped with basil leaves in the shape of a flower, but they had all kicked their bowls away and wouldn't take a single drop of the soup. Spike found that personally insulting seeing as how it took him half an hour to prepare the soup.
Twilight walked over to Rainbow first, and levitated the spoon and scooped up the spilled soup and tried to feed it to the rainbow-maned filly, but instead she just slapped the spoon away, moaning in disgust.
"You're gonna give me attitude, will you?!" cried Twilight. "Well guess what! Since you've refused to eat the soup Spike has so carefully prepared you, you'll have 15... no, 20 full minutes less of playtime!"
Rainbow gasped. "Wait, Twilight!" she said in a high-pitched voice. "I didn't mean it! I'm eating all the soup! See?!" With that, she immediately tipped the bowl back into place and gobbled up the soup messily, dipping her hooves into the bowl and sticking them back in her mouth so she could suck the soup off of them.
"That's what I thought." Then, she turned back to the rest of the fillies. "That goes for the rest of you too. I don't wanna see a single drop of leftover soup, and you'll have to clean the tablecloth after you've finished eating, too. Spike will help you in case it's hard."
Everyone quickly did the same as Rainbow, then, afterwards, they cleaned the tablecloth in the kitchen where Spike and Twilight cooked. Finally, they headed to the throne room in excitement and had fun.
In the meantime, while all the fillies and Spike were distracted, Twilight decided to check out the book and see for a counterspell. What Twilight saw, however, was something truly surprising.
It turned out that the age regression spell in the book was permanent and, once the pony was affected, they could never change back to their normal age. Twilight wished she had read that part before she had just decided to randomly test it out.
Twilight couldn't understand. She didn't imagine Spike would, either, and she had now idea on how to explain to Apple Bloom, Sweetie Belle and Scootaloo that their older sisters had been turned into foals a little younger than they were,
Twilight immediately shut the book and put it back on the shelf.
She broke into a cold sweat and barged downstairs, then to the throne room.
"Girls?!" she cried.
They all stopped what they were doing and turned to Twilight, pure innocence and cluelessness composed their eyes.
Fluttershy had been playing princess with Rarity and Pinkie, Applejack and Rainbow Dash had just had a race and were arguing whether using wings in a race was cheating or not.
They hadn't been up to anything mischievous, or were acting out of character for a pony that age at all for that matter.
Twilight breathed a sigh of relief and left.
The rest of the day so far had been good.
After playtime they had naptime, then they were read stories and finally they had another naptime, then ate dinner, than went to bed.
The fillies had to sleep in a few spare beds Twilight had, and, just as Twilight was starting to doze off after pondering on what to do with the fillies now that she was officially their mother, she heard the door creak. She opened her eyes wide open and saw a little Fluttershy standing at the doorway, looking upset as she clutched a plushie of Angel Bunny in her hoof.
"What's wrong?" grunted Twilight, not so pleased from being awoken from her slumber.
"Um... I had a nightmare," said Fluttershy sheepishly.
Silence dawned upon them.
Twilight beckoned the filly with her hoof and with that, she walked over to Twilight and crawled on her bed.
"You can sleep with me tonight and you can tell me about the nightmare in the morning, okay?"
Fluttershy shyly nodded and cuddled next to Twilight, still clutching the plush close to her.
Twilight couldn't help but smile at the little filly and she hugged her close to her, and they had a restful slumber for the rest of the night with no nightmares.