A resident of Saint-Laurent, Quebec since 1965, where she operated a successful insurance brokerage firm in partnership with her husband Renė Maheu, Senator Maheu was a founding member of the Saint-Laurent Chamber of Commerce and served as its first Vice-President.
She was also active in a number of local and national community groups and charities including Boy Scouts of Canada.
Sitting on the opposition bench, she served as the Liberal Critic for Multiculturalism and Citizenship.
Re-elected in the renamed riding of Saint-Laurent—Cartierville during the 1993 election that brought the Liberals to power under Jean Chrétien, she served as Deputy Chair of Committees of the Whole from January 1994 to February 1996, with one of her roles being assistant deputy Speaker of the House of Commons.
In 1996, she was appointed to the Senate of Canada on Chrėtien's recommendation in order to give "star candidate" Stéphane Dion the opportunity to contest a by-election to fill the vacancy in the House created by Maheu's appointment.