At the age of twenty-two, she entered the Poor Clare monastery in Valenciennes, taking the religious name Joséphine.
[1] When the monasteries and convents were suppressed during the French Revolution, she fled to her family in Mons, Hainaut, as did her sister.
When Austrian forces took the city, there was a brief period of peace, and Joséphine returned to Valenciennes in 1793.
Since her own Poor Clare monastery had been destroyed, she and her sister resumed religious life at the Ursuline convent.
[1] The revolutionary army retook the city and in 1794, she and several other nuns were arrested on the grounds that they were emigres who had returned without permission and were running a religious school.