Bloodfire Blood Destiny Series, Book 1.

Mack might be, to all intents and purposes, a normal looking human, but she lives with a pack of shapeshifters in Cornwall in rural England after being dumped there by her mother when she was just a young child. She desperately wants to be accepted by her surrogate family, not least because a lot of them hate her for merely being human, but for some reason her blood just won't allow the transformation to occur. With a terrible temper to match her...