This marked the beginning of a very painful period in her life, with the further loss, within seven months, of her father, uncle and eldest son.

She found great peace and satisfaction in the monastic life, but, after six months, she became very ill and had to leave the monastery.

She then went to live on her estate La Mothe Lusié to recover her health, and where she adopted the lifestyle of a secular dévote, performing many acts of charity, including food and alms distribution, and regularly met with young women of her social class to pray and discuss religious questions.

She sought for models of Catholic women to be her guides and cultivated an interest in the lives of Scholastica, Clare of Assisi, Catherine of Siena and Teresa of Avila.

The Jesuits asked de Lestonnac to serve as founder of a new teaching order for young women.

[4] The group purchased an old priory near the Château Trompette,[5] but moved in September 1610, to a larger old monastery on rue du Hâ.