She was the only female filmmaker on the National Film Board of Canada in the 1960s and 1970s. Her first film, the black and white surrealist fictional documentary "De mère en fille" (1968), critiques social codes of motherhood and investigates the psychological experience of pregnancy. The film had a significant influence on the nascent feminist movement in Canada. "De mère en fille" is the first feature film ever directed by a French-Canadian woman. Poirier's film "Mourir à tue-tête" competed in the Un Certain Regard section at the 1979 Cannes Film Festival. "Mourir à tue-tête," which aboards the subject of rape, remains Poirier's best known film. Her 1974 film "Les Filles du Roi" explores a history of masculinity in Quebec. In 1996, she directed the feature-length documentary "" to understand the events that led to the murder of her daughter.