[4] The Liberals won a majority government in this election under David Peterson, and O'Neill served as parliamentary assistant to the Minister of Education in 1987–1988.
The Liberals were upset by the New Democratic Party in the 1990 provincial election, although O'Neill was comfortably re-elected in her own riding.
[5] She served as Deputy Opposition Whip from 1990 to 1992, and held a number of official critic positions.
[6][7] She went on to serve with Elections Canada as the Federal Returning Officer for the electoral district of Ottawa West Nepean.
She died from cancer on September 6, 2010, at the Cumberland Regional Health Centre in Amherst, Nova Scotia at the age of 74.