Blood magic - Tessa Gratton

The murder of her parents has left Silla damaged and lost, and Silla's insistence that her father is not to blame only alienates her further from her friends and family. When a mysterious spell book arrives, Silla hopes it will lead to some answers about her parents' killer. In her first attempt at magic, in an old graveyard near her home, Nick, the new boy in town spies on her; he recognizes the magic that Silla is performing as the same magic his mother performed with him, before she went mad.

Before long, Silla and Nick connect, though Nick is unwilling to share his history with blood magic with Silla. When Silla's friends start showing signs of possession, Silla, Nick and Silla's brother, Reese, must contend with a deadly, immortal woman who will stop at nothing to take the book of spells from them.