She first came to notice when she was cast as Jenny Wilder in Little House on the Prairie, which she followed up with roles in films such as Heathers. She starred on the Aaron Spelling-produced Beverly Hills 90210 for four years, from 1990 to 1994. Although her departure from the series was reportedly acrimonious, it didn't stop Spelling from casting her in another series Charmed. She left that series in 2001, after three years, claiming that her best work was being wasted on a show "for 12-year olds." She now hosts "Scare Tactics" on the Sci-fi channel.
Her private life has also been turbulent, with a six month marriage to Ashley Hamilton, son of George Hamilton.