Off trots Blueberry.
"See if you like any of those," she says. "I wouldn't mind giving them up to be amulets."
There are a variety of interesting pendants inside, all sized to be worn by little ponies and therefore more or less basically wearable by a medium-sized human. Some of them would actually be a bit big on Emily.
She pores over the relevant section of the artifacts book.
"There," she says, when she's read the whole section through twice more. "All set. Goodness that spell is complicated. Just set your necklace down on the floor, please, and I'll cast the spell on it."
The new amulet flashes once with pale blue light, and then settles down to a barely-there shimmer. "Oof," says Blueberry. "That was hard. All done! Enjoy your new amulet!"
"It only works when you put it on, and even then it waits to turn you into your true form until it would be reasonably safe and comfortable for you to be your true form right then," says Blueberry.
"Like not falling out of the sky, or not being a sea serpent on land, or not being a dragon underwater."
"Well, I guess either that's your true form or your true form is something that has trouble moving around on land or doesn't breathe air or is too big to fit in the library," says Blueberry.
"Neat!" says Blueberry.
Blueberry giggles. "Were you stuck as a human for a long time? Do you want to go outside and fly?"
"There's griffins! Not very many of them nearby, but they're not unheard of. And Ponyville is a nice, friendly town, I'm sure nopony will pester you."
The sky is clear of both clouds and ponies, except for a far-off grey pegasus.