The Ropers -- Stevie Vallance as "Jenny" (season 2)
Stevie Louise Vallance as "Jenny Ballinger" was added late in the game to The Ropers (9 episodes in season 2) when Helen and Stanley discover her living in the their attic. Mrs. Roper feels a maternal connection with Jenny and convinces Stanley to let her live with them. Unfortunately the series was cancelled before season 3 when Jenny would have become a regular. (ABC)