Angel by Cliff McNish
Not fit to be a daughter. Not fit to be a friend. Not fit to be an angel. Two girls are inextricably linked by destiny, not choice.
Stephanie is friendless, strange, a misfit.
Freya can't stop seeing angels.
But when one of those angels begins to stalk her, its shadow following her everywhere, Freya is forced to make decisions from which there is no turning back.