Demonglass (Hex Hall #2) by Rachel Hawkins

Sophie Mercer thought she was a witch.

That was the whole reason she was sent to Hex Hall, a reform school for delinquent Prodigium (aka witches, shapeshifters, and fairies). But that was before she discovered the family secret, and that her hot crush, Archer Cross, is an agent for The Eye, a group bent on wiping Prodigium off the face of the earth.

Turns out, Sophie’s a demon, one of only two in the world—the other being her father. What’s worse, she has powers that threaten the lives of everyone she loves. Which is precisely why Sophie decides she must go to London for the Removal, a risky procedure that will either destroy her powers forever — or kill her. /DIVDIV

But once Sophie arrives she makes a shocking discovery. Her new housemates? They’re demons too. Meaning someone is raising them in secret with creepy plans to use their powers, and probably not for good. Meanwhile, The Eye is set on hunting Sophie down, and they’re using Acher to do it. But it’s not like she has feelings for him anymore. Does she?