Hélène Monastier was a teacher at the Vinet School from 1904 to 1943. From 1905, she also gave lessons to young apprentices and workers at the Maison du Peuple. She met Christian socialists during a Paul Passy conference in Lausanne, and helped to create a local group. In 1914, she became the first president of the Federation of French Christian Socialists. She participated in May day processions.