Changeling (The Dark Fae Series)

Trapped in a teenage body by magic, Maggie has spent nearly a century as the human pet of the Fairchilds, a clan of faeries. As the oldest changeling in the house, Maggie knows that survival depends on playing the game of life like a faery: Cheat when you can and don't get caught. But what will become of her and the rest of the changelings when six of the Fairchilds are murdered?There isn't always a happily ever after.