When Susan Saint James became pregnant during the show's fourth season, it was not written into the show because her character was single. She was filmed either with strategically placed props or by having her character Kate recovering from a broken leg. However, in a flashback episode that took place when Kate and Allie were younger and they were pregnant with their daughters on the show, St. James was allowed to show her pregnancy.
John Loeffler, who sings the signature theme song at the end of the show, appears as a piano teacher in the second series episode "Piano Lesson." He sings a few other songs during the course of the episode, in addition to the regular end theme.
Allison Smith was a veteran Broadway musical stage performer before she was cast in the series. One episode allowed her to sing by having her character audition for and be hired as the singer of the pop band. The song she sang was "Goodbye to You" by Scandal.