Moon Academy by Catherine Banks

Being adopted by a werewolf pack means Sarah’s life is never simple.
No one ever said that living with werewolves was easy, but being the last witch certainly doesn’t make it any easier.
With Nick by her side, Sarah is sent off to Moon Academy to be trained – and observed.
Vampires, the fae, and a mysterious and secretive third party evidently have big plans for her, whether she likes it or not.
In the coming year, she’ll need to keep her wits about her, learn to control her magic, and choose Guardians who can protect her against the threats she faces as the last of the witches.
The truth will always come out, and Moon Academy is no exception.
The first 5 chapters of this story were previously published in the Realms & Rebels boxset.