In season 1 Caroline's mother Margaret Duffy is a slim blond cultured mid-west American lady - but when she returns in Season 3, she has become a short dumpy red-haired German-American woman with a peculiar squeaky little accented voice, and an obsession for collecting tacky knick-knacks.
In season 1 Caroline loves opera and enjoys going and has a minor argument with Del as he didn't want to go with her. In season 3 when Julia is setting Caroline up with Trevor, Trevor asks Caroline if she wants to go to the opera with him and before she has a chance to answer Richard states that she hates opera and implies that she has never been to see one.