Mirrors and Mysteries (Fairy Tales of the Magicorum Book 9) by Christina Bauer

…Instead, Grayson now teaches at the Thornfield home for shifter orphans. Even better, her boss is none other than the sexy alpha, Dex. It’s all good until a mysterious witch, Jocasta, appears in a nearby tower, demanding that Dex and Grayson discover the true nature of all Rapunzels. If not, Lady R will return to claim Grayson… and Thornfield will be wiped out by the evil Prism Master…