I am a descendant of Jean Gauthier and Marie Marguerite Pressau as well as from Jean's brother Joseph who married Marie Fortier. Pierre Gaultier and Charlotte Rousell are their adopted parents. Their actual parents were killed fighting the Iroquois. Their names are Joseph Saguirou and Agnes Maxoumitimousens. They are Algonquin. Agnes is likley also Mascouten.
This info is also in Carrying the Chalice Forward and other Secret Stories of North America.