Born in Rivière-du-Loup, Laurette was the daughter of William Lachance and Clara Chouinard. She studied music and domestic arts with the Sisters of the Notre Dame Congregation in Saint-Pascal of Kamouraska. Very talented in music, Laurette obtained a diploma from the Montreal College of music. After teaching music in Saint-Pascal and at the Academy of Saint-Basile, she became a Religious Hospitaller in 1922. She continued to teach music and even became head organist.