Before I posted the last "You Know the Voice" installment the other day, I had done some research on Janet Waldo's "face acting" career. As I noted, her appearances on I Love Lucy & The Lucy Show aren't available on YouTube or any other site at the present time. She had a voice cameo during season 1 of Get Smart, so that was out. So, we had to move back in time a little.
During season 3 of The Andy Griffith Show, Janet guest-starred in the episode, "A Wife For Andy", which, in turn, began the ongoing subplot of Sheriff Andy Taylor (Griffith) courting school teacher Helen Crump (Aneta Corsault), who was Opie's teacher. The basic idea in this episode, with Barney (Don Knotts) scheming to play matchmaker for Andy, was lifted nearly 30 years later in the movie, "Problem Child 2", with John Ritter. Janet plays Amanda, who is led to believe that Barney's girlfriend, Thelma Lou, was to meet her at the Taylors' house.
I think it was this episode that led to Janet being cast the next year on ABC's Valentine's Day........
Edit: 11/24/14: I had to replace the video, and this copy doesn't have the opening credits to avoid copyright issues.