In 1966, Singleton was teamed again with Ball on The Lucy Show in the episode, "Lucy and Art Linkletter", in which she plays Ruth Cosgrove, an Actress whom Linkletter hires to help Lucy with a stunt on his television series. In an interview in The Lucy Book by Geoffrey Mark Fidelman (Renaissance Books, p. 233), Singleton revealed that she had originally been hired to be a regular on Ball's third series, Here's Lucy, in 1968. Ball would have played a dumb secretary and Singleton the more intelligent one, but the premise was dropped when Ball decided to cast her own children in the show. She did, however, appear in the series premiere episode, "Mod, Mod Lucy". On March 4, 1974, she appeared in episode 22 of season 6 entitled "Lucy Carter Meets Lucille Ball".