Thelma (Suburban Hell)
From Tardis Wiki, the free Doctor Who reference
Thelma was a neighbour of Belinda. Belinda wanted to ask her what had happened to the previous owners of the house. She could create a psychic barrier when the Fourth Doctor travelled back to 1977. She died when the Acolyte came back for Belinda. When time was reset, she didn't die and was the adopted mother of Belinda. (AUDIO: Suburban Hell)