Fourès was born in Pamiers on March 15, 1778 to Marguerite Brandon and Henri Jacques-Clement Bellisle, a clockmaker. She worked as a milliner and married Jean-Noel Fourès, a cavalryman who was on leave from military duty. When Jean-Noel was called back to active duty during the couple's honeymoon, Fourès accompanied him on the French army's trip to Egypt. As the soldiers' spouses were not permitted to come on the transport ship, Fourès wore a Chasseur uniform to disguise herself, successfully remaining undetected for 54 days until the expedition's arrival in Alexandria.