Though there is no record of McxGillivray having married in the Scottish Presbyterian tradition, he took as a consort a high-status Creek woman named Sehoy Marchand. Their marriage was recognized by the Creek. Early biographers claimed Sehoy Marchand was the daughter of a French officer at Fort Toulouse named Jean-Baptiste Marchand. Her mother was also named Sehoy, and she was a high-status woman of the "Koasati" (alternative spelling: Coushatta), of the Wind Clan. Hers was a politically powerful family of the Upper Creek nation, which had matrilineal system of descent and property. Sehoy's immediate family included several important chiefs. The marriage was a strategic alliance for her family as well as for the ambitious trader; she could protect her children within the tribe.