Confessions of a Dangerous Girl by Dan Birk
Emma has spent most of her life in a boarding school, that is supposed to be for child psychopaths, but it's actually an undercover CIA training facility. They are supposed to help kids like Emma to become better people, but in reality, they are training them to be assassins.
Emma's latest mission takes her back home when she has to go undercover at a local high school and pose as a normal student. She needs to get into Model UN, so she will have access to her target. But something like that is much harder for Emma than anticipated. She never made real friends and her first attempt failed miserably.
To get into the club, she convinces the best student, to help her become a better person, while she will help her get a guy she likes.
Slowly but surely, Emma changes. She learns how to make actual friends and starts to do good, but the mission should always come first.
The story is told from Emma's POV, so you really get into the head, her reasoning for why she does what she does and why she reacts the way she does. The more you get to know her, the more it is evident that there is more to her than just psychology and there is a way she is not all bad. And soon you can't help but root for her.
My favourite moment was with her grandma, that put it all in such a nice perspective. :)
Highly recommend it, it's awesome! :)