Grandma Thora is Arthur, D.W., and baby Kate's paternal grandmother and Loretta and David's mother, who is quite caring, but is a poor cook, as revealed in the episode "The Half-Baked Sale." Despite this, she was able to bake Arthur's birthday cake in one episode. She is a columnist. In a flashback in Clarissa is Cracked, Thora had three brothers. Gramdma Thora is David Read's mother. It is revealed in "April 9th" that she had gotten in a car accident (but was not hurt) when David was Arthur's age. Grandma Thora is based on Brown's own grandmother Thora, who encouraged him by saving his childhood drawings in a bottom drawer.