When Bundle of Joy premiered in 1956, Debbie Reynolds and Eddie Fisher were the cutest young marrieds in Hollywood, the obvious choice to headline the musical remake of one of the great comedies of the '30s, Bachelor Mother. As the Prince Charming of the piece, Fisher proves that as an actor, he is a pretty good crooner. But Reynolds is warmly appealing in the role originated by Ginger Rogers, playing a salesgirl who picks up a foundling, is mistaken for its unwed mother and must keep up the charade - baby and all - to keep her job. Coincidentally, Reynolds discovered she was pregnant before filming began. In true trouper fashion, she was still hoofing up a storm on the soundstage when she was seven months along.