SOLVED. YA possibly Dystopian. Plot takes place in a Ballet academy where students are controlled and (I don't remember if this was the case) subjected to human experiments. Spoilers ahead. [s]

[Lucy]

Details:
1. I read this several years ago
2. The ballerinas all have an asterisk-shaped marking on their wrists, which is the exact shape of a key that the main antagonist (the headmaster) has. The girls find the key in the end and unlock secrets.
3. At one point the protagonist was complaining about her dress before/after a dance recital, saying that it made her look like "a dying tulip".
4. In the end, the girls rebel and escape the academy. (And perhaps they also burned the school down-I don't remember)
5. It's a bit similar to the Girls with Sharp Sticks series
6. If anyone could help me with this book, thanks a lot, because I just couldn't find it no matter how hard I look

[Juels]

The Midnight Dance by Nikki Katz

[Lucy]

Thanks a lot!

[Juels]

You're welcome.