Friesen was born in Oldham, Lancashire, in England, and moved to Canada at a young age, when her father, Reg Edwards, took up a teaching position at McGill University.
Friesen was employed by the National Museum of Canada from 1967 to 1973, and has been a faculty member in the University of Manitoba's Department of History since that time.
She was appointed Deputy Premier of Manitoba and Minister of Intergovernment Affairs on October 5, 1999, also receiving ministerial responsibility for Cooperative Development on September 25, 2002.
Also in 2002, she defended the provincial government's controversial decision to spray malathion in the Winnipeg area, as a means of controlling the city's insect population during an outbreak of West Nile fever.
She has subsequently returned to her teaching position at the University of Manitoba, and in 2004 issued a work entitled Magnificent Gifts: The Treaties of Canada with Indians of the Northwest, 1869-76.