The Serafina Series by Robert Beatty

"Never go into the deep parts of the forest, for there are many dangers there, and they will ensnare your soul."Serafina has never had a reason to disobey her pa and venture beyond the grounds of Biltmore Estate.There's plenty to explore in her grand home, although she must take care to never be seen. None of the rich folk upstairs know that Serafina exists; she and her pa, the estate's maintenance man, have secretly lived in the basement for as long as Serafina can remember.But when children at the estate start disappearing, only Serafina knows who the culprit is:a terrifying man in a black cloak who stalks Biltmore's corridors at night.
Serafina and the Twisted Staff Serafina's defeat of the Man in the Black Cloak has brought her out of the shadows and into the daylight realm of her home, Biltmore Estate. Every night she visits her mother in the forest, eager to learn the ways of the catamount. But Serafina finds herself caught between her two worlds: she's too wild for Biltmore and too human to fully join her kin. For Serafina to defeat this new evil, she must search deep inside herself and embrace the destiny that has always awaited her.