At the age of 7, Agnès Galand decided to dedicate her life to Our Lady of Le Puy-en-Velay. As a reminder of this vow, she took a chain from her father's workshop and wore it around her waist. When Agnès decided to join the newly founded Dominican convent of Langeac at the age of 21, she stopped wearing the chain, as her religious vows replaced it. Her piety and charity impressed the sisters, who chose her as their superior, and she fulfilled this task with great gentleness. In the meantime, she assisted women in childbirth, a skill for which she was famous.

In 1631, she received a vision from the Virgin Mary asking her to pray for the abbot of the nearby monastery of Pébrac, whom she did not know. Two years later, Jean-Jacques Olier, the founder of the Sulpicians, appeared to Sister Agnès. The two went to meet. Agnès died a few months later, but the Sisters of Langeac continue to pray for the members of the Sulpician congregation up to this day.

After Agnes's death, believers continued to ask for her intercession in case of difficult pregnancies, holding Agnes' chain in their hands. 1952. In 1991, the parents, who had been told by a doctor that the imminent birth of their child would endanger the lives of mother and baby, came to the monastery of Langeac to pray for Agnes's intercession, holding her chain in their hands. The birth took place without complications. This was recognized as a miracle and paved the way for her beatification in 1994. in.