Julia Frances Catherine Postel was born in a small French town near Cherbourg. After studying in a Benedictine convent, she returned home to teach school, though privately she dedicated herself to God’s service. Her calling became clear, with the onset of the Revolution, when her parish priest was forced to go underground. Postel pus herself at his service, setting up a secret chapel in her home, where clandestine services could be conducted. She herself undertook religious duties, such as carrying consecrated Hosts to administer to the dying. Thus, as Pope Pius X later commented, she served as a veritable “maiden priest.”
As the persecution receded, Postel devoted herself to repairing the local church, offering religious instruction, organizing prayer guilds, and performing works of mercy. In 1807, she determined that what she really wanted to do was to teach children, and for this she should organize a religious congregation. She joined with three companions in taking religious vows. Observing the rule of the Third Orde of St. Francis, they called themselves the Poor Daughters of Mercy. She became Mother Mary-Magdalen.
Thirty years later, their motherhouse was transferred from Cherbourg to a former Benedictine abbey in Courtance. Their new bishop urged them to replace their former rule with that of St. John Baptist de la Salle, and they changed their name to the Sisters of the Christian Schools of Mercy. After the order struggled for some years of dire poverty, the bishop urged them to disband. But Mother Mary-Magdalen persisted, and eventually their fortunes turned.
She died on July 16, 1846 at the age of eighty-nine. She was canonized in 1925.