She is the mother of Rayanne Leigh, the troublesome werewolf, and Professor of Transfiguration at the ACMA. It is in her blood to be a witch, her mother, her mothers mother and so on and so forth were all natural witches, but it was something her own daughter did not pick up.
She is a Metamorphmagus, (Metamorphmagi are born with the ability to change their appearance at will, The word comes from the Greek prefex "meta-" connotating change, "morph" meaning "form," and "magus" meaning "wizard.") and after some dealings as a youngster, not long after her daughter was born, she ended up working on the side of dark magics. A number of years later, this caused the death of her Muggle husband, a suspicious death.