Her father, Sir Alexandre Lacoste, became a Senator and her mother Marie-Louise Globensky, was a noted philanthropist.

Among her seven sisters were the noted feminist Marie Lacoste Gérin-Lajoie, the humanitarian Justine Lacoste-Beaubien and the businesswoman Berthe Dansereau.

[6][7] Chaired by judge Charles-Édouard Dorion, the commission was tasked with examination and reform of the Civil Code of Quebec as it pertained to the rights of women.

[6][8] In 1932, she was appointed by the Bennett government to serve as a Canadian delegate to the 13th conference of the League of Nations.

Some of Lacoste-Frémont's proposals in "Les droits" informed Marie-Claire Kirkland's Bill 16, which, in 1964, made substantial changes to Civil Code provisions regarding women's rights.