Thora's mother

Thora's mother is the wife of Thora's father and the mother of Thora and her three brothers. She is also the grandmother of David and his siblings; and the great-grandmother of Arthur, D.W., Kate, and their cousins.

Past life
In "Clarissa is Cracked," she is shown as a young mother from Thora's childhood.

Current life
In "Arthur's Cousin Catastrophe," she is shown as a present elderly woman at the family reunion, and later wins the egg and spoon race.

Arthur

 * 109b. "Arthur's Cousin Catastrophe"
 * 312b. "Clarissa is Cracked" (flashback)

Postcards from Buster

 * 135. "Family Reunion"