She starred as Susan Hartley in an episode of "Murder, She Wrote" and came back to the Disney screen in the sequel, "Honey, I Blew Up the Kid", as Amy Szalinski. Before this was written as a sequel to "Honey, I Shrunk the Kids", it was titled "Big Baby" and didn't have any characters from the original film. As the plot was changed to include the Szalinskis, there was no room for a female lead, besides Keri Russell's role as the babysitter. O'Neill only appeared in the opening scene as she is leaving for college. Her character is later mentioned in "Honey, We Shrunk Ourselves".