Ah, it's been a while since I've read this book.
Amari decides to steal the scroll because she sees her friend/servant have her magic awoken by touching the scroll.
(I'm assuming you've already finished the book, but if not spoiler alert)
In the end, she makes the right decision. She's essentially the reason that magic comes back.
Honestly, I probably wouldn't have done the same. Amari's father seems like a really cruel person, and I'd probably be too scared to steal the scroll.
-T.B.
