Rhea Perlman as Annette Lozupone
Annette Lozupone is Carla's sister (played by Rhea Perlman). She covers for Carla at the bar when Carla has her baby, although Annette has never waitressed before. Although she appears prim and proper, and Carla believes her to be innocent, she is actually "loose" (as Diane puts it.) Cliff is attracted and falls for her, but she gives her number to all the men in the bar, and she has the hots for Sam, making a move on him in his office. (Little Sister, Don't Cha)