Carnelian is the niece of The Duchess Of The Lake (Pearl). She is described as ugly, and feels unloved.
Her mother, the sister of the duchess of the lake, married a banker, and due to that fact, she lost all of her royal status, which Carnelian doesn't like. Her father died, and her mother committed suicide. She had no where else to go, so she went to live with her aunt.
Her aunt is The Duchess Of The Lake, and her cousin is Garnet. She hates Violet, and Violet served as her lady in waiting for a little while. Ash was her companion, and she is in love with him, after he left, Rye became her companion. She isn't loved by anyone, the royals always make fun of her, and the Duchess hates her.
She got Ash as a companion, and started to hate Violet. She turns in Ash and Violet, getting Ash thrown in jail.
The White Rose
She talked about by Ash and Violet, but is not in the book.
The Black Key
She is at the palace with Violet, and after a bombing that kills Violets old mistress, and she becomes Violet's new mistress, she breaks her shoulder, and back in the bombing. At the end of the book when the cities people take over the jewel, and Violet, Raven, Ash, and Garnet are faced with the Elector, and the Duchess Of The Lake. Carnelian kills the duchess because she hates her so much.