Image imported from derpibooru 
Original Description:
 
After Pipp accidentally applies a face mask product that ended up containing Fountain Of Youth water, which Pipp unknowingly collected from a lake she discovered while looking for magical ingredients for products, and the water had a magical essence so Pipp collected it, the water of course didn’t affect Pipp since she barely got anything on her, but Sunny, Hitch and Izzy volunteer to try the product and well, they de age into foals. Which Pipp quickly learns they’re a lot of work and without the knowledge of what caused their de aging, she calls Zipp to take the foals back to the Crystal Brighthouse until Pipp could get back.
 
Well, Zipp it turns out had just as much of a hard time as Pipp and by the time her sister got home, Zipp looked like she was about to loose it, her mane messy, her coat messy, and bloodshot eyes. The two sisters become their temporary caregivers for the time being and they learn that it’s hard to get foals to do anything they want them to. Refusing to eat when given food, taking almost an hour to fall asleep, and throwing lots of tantrums, especially when getting bathed or when they’re made to stop the current activity.
 
It was meal time and the Pegasus Sisters made the foals oatmeal, well let’s just say the foals won’t eat it. Izzy immediately plays with the food and gets it in her mane, while Hitch is staring at Pipp with a scowl, and Sunny sucking her hoof, not noticing her food at all. Pipp has about lost her mind at this point as she just wants them to eat a healthy meal for once. She sounds calm but on the inside is loosing her sanity.
 
Hopefully they find a cure soon, which Zipp has been investigating but it’s taking her awhile to figure out what is going on, but so far she has a lot of theories.
 
And yes, it’s based off the episode from the online YouTube series, My Little Pony: Tell Your Tale, but unlike the events that happened in the episode, it takes Pipp and Zipp several days to figure out why their friends de aged. And also, I don’t consider Tell Your Tale canon to my AU, instead, there are some elements that are based off of the events from those shows, but my universe stays more in sync with the Netflix Series, My Little Pony: Make Your Mark and Friendship is Magic.
 
Here’s the episode it’s based on:
 
https://youtu.be/_C3VpQs8uJI