The fourth of eight children born to Julien, a court magistrate, and Françoise Lecocq, a notably pious mother; one of Marie-Louise’s brothers became a priest, one of her sisters a nun; her eldest sister, Jeanne, was paralyzed at the age of 13, but was cured at 16 during a pilgrimage to Notre Dame des Ardilliers, Saumur, France. Educated from age seven by the Sisters of Sainte Jeanne de Lestonac. From the age of seventeen, Marie-Lousie devoted herself to the care of the poor and the sick, and when she worked at the poor house in Poitiers, France, a place known as a the General Hospital, she met and began to work with Saint Louis de Montfort. On 2 February 1703, at age 18, she dedicated herself to God and moved into the Hospital, officially as an impoverished inmate, but actually to help Father Louis administer the place. With him she co-founded the Congregation of the Daughters of Wisdom, was it’s first member, and served as its first leader.
De Montfort left to serve as a travelling missioner, and Sister Marie-Louise worked as nurse and administrator on her own for the next ten years. She expanded the mission of the Hospital to feed beggars and operate the Hospital of Niort in Deux-Sèvres, France. In 1715, she and Catherine Brunet left Poitiers for La Rochelle, France where they opened a free religious school; it soon had 400 students. Upon the death of Saint Louis de Montfort, Marie-Louise assumed full leadership of the Daughters of Wisdom. She returned to Poitiers in 1719, and established the mother-house of the Daughters in Saint-Laurent-sur-Sèvre, France in 1720; the house still stands, and is a museum of the Daughters. The Daughters lived and worked in abject poverty, but the Congregation continued to grow. From 1729 to 1759 thirty new houses of Daughters were founded, and they became known for teaching children, caring for the sick, and feeding the poor, all for free. Their houses became homes for orphans, the neglected elderly, and abandoned cripples.
At age 66, Mother Marie-Louise made a journey on horseback to all the Daughter communities to inspire the sisters. Returning home, she had an accidental fall that left in continuing pain, and broke her health. At her death, the Daughters had 174 sisters and 37 houses, and they have continued their good work in France, Spain, Prussia and Belgium for centuries.