According to Brian Eppes, production for The Backyard Show (1988), Three Wishes (1989), and A Day at the Beach (1989) began production at the summer of 1988.
Sandy Duncan makes her first of 3 physical appearances on screen as Amy and Michael's mother the other two would be A Day at the Beach and The Backyard Show she does not appear in Waiting for Santa, Rock With Barney, Barney's Campfire Sing-Along, Barney Goes To School and Barney in Concert but she is mentioned by Michael in Waiting For Santa
The second of the Barney & the Backyard Gang videos to be released and the 3rd one to be produced.