Continuity mistake: Peggy Hill's mother seems to change over the course of the show. Prior to the ninth season, whenever Peggy's mother is seen (in the present or in flashbacks), she is portrayed as an older version of Peggy. In the ninth season's premiere episode, Peggy's mother is a lean, leather-skinned rancher who disdains Peggy and lives on a secluded ranch. The change in facial features and appearance is too much to just be a change in style as well.
Trivia: During Hanks's conversation with Bobby when he tells him that he will have to marry Luanne, look at the shelf behind Bobby. There is a Bart Simpson doll there. A few years before this was featured the Hill family was in the crowd at one of the pee wee football games in the Simpsons episode "Bart Star".Lummie