Thouret was born in Sancey, in the Franche-Comté region of eastern France, on November 27, 1765, the fifth child of a poor[2][3] and "deeply Christian family".

[4] Thouret "felt a strong attraction to the stricter religious life and at the same time to the service of the poor"[1] at a young age.

When she was 22, against the wishes of her family who wanted her to marry, Thouret entered the Daughters of Charity of Saint Vincent de Paul to serve the poor and work in hospitals, first in Langres and then in Paris.

[2][3][4] While a postulant, she had what she described as her first "encounter" with St. Vincent de Paul, establishing what she considered the close father-daughter relationship with him that lasted her whole life.

Pope Pius VII approved their community, which he named “Sisters of Charity under the protection of St. Vincent de Paul", on July 23, 1819.