Welma Thornwood was the Woodtroll nanny of Maris Pallitax. She appeared several times throughout the events of The Curse of the Gloamglozer. During the events of The Winter Knights, Heft Vespius fraudulently gained control of the estate of Linius Pallitax and fired Welma, and she took up work in Undertown with Tweezel, seizing every opportunity she could to check on Maris in secret.
Welma was generally a kind and caring individual. She loved Maris deeply and often acted as a mother figure to her, frequently comforting her when she felt neglected by her father.