The Cruel Prince by Holly Black (Folk of the Air #1)
Jude was seven years old when her parents were murdered and she and her two sisters were stolen away to live in the treacherous High Court of Faerie. Ten years later, Jude wants nothing more than to belong there, despite her mortality. But many of the fey despise humans. Especially Prince Cardan, the youngest and wickedest son of the High King. To win a place at the Court, she must defy him, and face the consequences.