Karen Brown is a character on Beverly Hills, 90210. She did not physically appear in the series, but was mentioned.
Karen was the biological mother of Steve Sanders, having had an affair with Rush Sanders while she was in high school, resulting in Steve being born. She gave him up for adoption, at which point Rush paid to adopt his own biological son.
After high school, Karen went to college in Albuquerque, New Mexico and then married a man named David Mulligan. She died in a car accident on January 20, 1989.