Broken Spire - Sue Perkins

Immediately prior to her first year at Spires Magic College, Ash discovers her parents adopted her as a toddler. This explains her silver purple hair which sets her apart from her peers. Despite working hard at her studies, the Spires magic seems wrong to her and the maeven consider her style of magic to be alien and some of them try to expel her. Ash is compulsively drawn to the ruined North Spire but students are not allowed anywhere near this ruin.  She believes the broken spire holds the answer to her origins, but doesn’t want to get thrown out of Spires for breaking the rules.
Her boyfriend Orm, another talented student, promises to help her enter the North Spire at the end of their time at Spires, but will Ash’s alien magic get her expelled before then and end her dreams of discovering her past?