She served on the Winnipeg City Council for fifteen years, and ran for the Legislative Assembly of Manitoba on two occasions as a candidate of the Liberal Party.
She was endorsed by a centre-left group called the Civic Reform Coalition, while Dennehy was part of the governing centre-right Independent Citizens' Election Committee.
[1] She also criticized a report by retired judge Ted Hughes into the mismanaged prosecution of a Winnipeg attorney for what turned out to be an unfounded accusation of sexual assault.
[4] She opposed unrestricted Sunday shopping for Winnipeg,[5] and strongly criticized a plan to cut a traditional Christmas bonus for welfare recipients in late 1993.
She opposed Al Golden's 1993 proposal to remove a baseball diamond from an historical site on the park grounds, arguing that the field was needed for children's recreation.
[10] She was later skeptical of a proposal to turn Louis Riel's birthplace near the park into an historical landmark, on the grounds that it could prevent the construction of a soccer field in the area.
[16] Although considered a strong candidate, she was hurt by her party's weak provincial campaign and finished second against Progressive Conservative incumbent Jack Reimer.