Therese (b. 1775) and Magdelaine, the two youngest children, were baptized as Roman Catholic a few years later on August 1, 1786, on Mackinac Island. They were raised in their mother's culture and learned several languages. Their father had sent the family's children to Montreal to be educated in French-language schools, but their widowed mother did not have the financial resources to do that when the girls came of age. She moved to Mackinac with Magdelaine and her sisters after the British abandoned Fort St. Joseph, ceding the area to the new nation of the independent United States in the aftermath of the American Revolutionary War.