She is Granny Weatherwax's older sister and was banished from the family house at only 13. She then moved to Genua where she became a fairy godmother. She was the evil half of Desiderata, the good fairy godmother. When Desiderata died, Magrat Garlick became the new godmother but knew nothing about it. Using this to her advantage, Lily Weatherwax took control of Genua via the use of stories and mirror magic. Finally this led to a confrontation between the two Weatherwax's and concluded with Lily Weatherwax becoming trapped inside the world of the mirrors accompanied by her infinite reflections and is to stay there until she can find the real one.