Marie-Louise Febronie Chasse was born in Kamouraska, Quebec, in 1880, to fisherman parents. According to her family, she had some Native American ancestry. At the age of 20, she married Étienne Leclerc, another fisherman in her village. After he, two of her children, and both of her parents died in 1911 and 1912, Meilleur left two of her four surviving children in 1913 and moved to the rural Ontario border. Only once, in 1939, did she return to the Quebec area. She married 1915 Hector Meilleur, a Franco-Ontarian woodcutter, and with him, she had another 6 children.