The Waltons Season 6 Episode 7

Mary Ellen gives birth to the Waltons' first grandchild, John Curtis Willard. However, Cassie, a lonely and superstitious teenage neighbor whose premature baby girl was stillborn, believes John Curtis was sent to replace her own baby and she kidnaps him. It is up to Olivia to gently explain to Cassie that someday Cassie will have another baby, but that John Curtis is really Mary Ellen's.