The young actress started her first entry into regular series work with the CBS sitcom "Lenny" (1990-91), playing the streetwise eldest daughter of a blue-collar Bostonian. By the time "Lenny" ended its run, von Oy was already a regular on NBC's "Blossom", giving a performance that would earn the actress many fans. She brought just enough charm to the boy-crazy, neurotic teen to keep the character just this side of annoying, and despite reported tensions on the set, was noted by many related to the show to be a talented and exceptionally professional performer.
In 1995, von Oy lent her voice to the character of fast talking teen Stacey in the animated feature "The Goofy Movie", suffering from a bit of typecasting. She would go on to do additional voice acting on the ABC Saturday morning animated offerings "Disney's Pepper Ann" and "Disney's Hercules". Back in front of the camera, on the small screen, the actress moved to the college level, featured in the campus-set NBC TV-movie dramas "She Cried No" (1996) and "Dying to Belong" (1997). A memorable guest stint on "Chicago Hope" as a teen who throws her newborn baby in the trash proved von Oy's talent. She retread the unwed teen mother ground on a 1998 episode of "7th Heaven" in 1998.
1999 saw the sprightly performer return to regular series television, playing the off-beat college student Stevie on "The Parkers" (1999- ), a spin-off of "Moesha". Originally a recurring player, von Oy became a regular part way through the premiere season of the popular UPN series.