Oleynik began her screen acting career age at 12, in a 1993 episode of the television series Dr. Quinn, Medicine Woman; the same year, she also appeared in the made-for-television film, River of Rage: The Taking of Maggie Keene, and was subsequently cast in the lead role of the series The Secret World of Alex Mack, playing a teenage girl who receives telekinetic powers as a result of an accident. The series ran on Nickelodeon from 1994 to 1998, and was one of the network's top three most watched shows, becoming a favorite among teen audiences and turning Oleynik into a teen idol. During the show's run, she played one of the lead characters in the 1995 feature film, The Baby-Sitters Club (opposite Rachael Leigh Cook and Schuyler Fisk), appeared in several episodes of Boy Meets World, wrote an advice column for Tiger Beat magazine, and was involved in Nickelodeon's Big Help charity, Hands Across Communication, Surfrider Foundation and the Starlight Foundation. She has commented that s