She is best known because of a printed correspondence addressed to her father that was published and attributed to her by the Rouen printer Antoine Le Prévost in 1728.
Two Ursulines from Rouen, Marie Tranchepain de St. Augustin and Marie Anne Le Boullenger de St. Angélique, had traveled to Paris in March 1726 to sign a contract with the French Company of the Indies (previously known as the Mississippi Company).
The Ursulines hesitated at first because the demands of establishing a mission were difficult enough for experienced nuns and she was not even a member of their order.
The Ursulines were traditionally a teaching order, but they contracted with the Company of the Indies to run the military hospital in New Orleans, thus further complicating the mission.
[3] After examining Marie-Madeleine for three months "during which they neglected nothing in order to know her well" the Ursulines agreed to let her join the mission.