Wings - Aprilynne Pike

When a flower blooms in the middle of her back, Laurel discovers that she is a faerie and was placed with human parents as a child. As Laurel learns about her true background and the dangers that face the faerie realm, she struggles to find her place in both worlds. Laurel was mesmerized, staring at the pale things. They were terrifyingly beautiful--too beautiful for words. Laurel turned to the mirror again, her eyes on the hovering petals that floated beside her head. They looked almost like wings. Laurel's life is the very definition of normal . . . until the morning when she wakes up to discover a flower blooming from her back. As it turns out, nothing in Laurel's life is what it seems. Now, with the help of an alluring faerie sentry who holds the key to her true past, Laurel must race to save her human family from the centuries-old faerie enemies who walk among them.