TVLine reports that Ellen Burstyn will play perhaps the oldest mom in the Plunkett family on Mom this season. She’s been cast as Bonnie’s (Allison Janney) estranged mother Shirley, who abandoned Bonnie when she was only four. Shirley’s return will create problems for Bonnie and Christy (Anna Faris), and she’ll have a rival for her granddaughter’s affections in June Squibb (The Jack And Triumph Show), who will appear in the same episode as Christy’s idea of the perfect grandmother. So far Burstyn is only scheduled to appear in the November 19 episode, which means there will be plenty of unresolved issues left on the Thanksgiving dinner table (we assume that’s where they’re going with this November date). Mom returns to CBS for season three on November 5.