The sweaters worn by Beverly belonged to the real Beverly Goldberg.
Although the show is largely based on series creator Adam F. Goldberg's family, they had three sons: Adam, Barry, and Eric. ABC executives told the creators to make one of the siblings a girl because the show would be funnier. So Goldberg made the siblings Adam, Barry, and Erica.
The real life Jackie Geary (Adam's high school girlfriend) can be seen in several episodes playing her own mom.
Murray Goldberg was a doctor in real life, not the owner of a furniture store.
In the season 2 episode "Barry Goldberg's Day Off" (a spoof of Ferris Bueller's Day Off), Charlie Sheen reprises his role as the arrested drug addict in the police station. After talking to Erica, he is told he's free to go. He responds by saying, "Finally! Feels like I've been sitting here for 30 f***ing years." The episode aired roughly 29 years after the release of Ferris Bueller's Day Off.