When Bonne d'Armagnac was born in Carlat, France, her parents took a vow to give her to religious life, a vow conditional upon the girl's own subsequent assent. When years later the young woman learned of her parent's promise, she at first refused to consent to it. But she later had a change of heart, and decided of her own accord to enter the convent of Poor Clares at Lezignan. There she encountered opposition from her brother James, who began a campaign to persuade her to abandon convent life. Her vocation thus tested, Bonne persevered in the novitiate, developing a deep devotion to the Passion of Christ. On the day of her religious profession, she had a mystical experience in which Christ revealed his love for her, and forewarned her of her father's approaching death. Bonne herself was soon stricken with a fatal illness, in the course of which she redoubled her meditations upon the Passion, finding great consolation therein. On her deathbed, the twenty-three-year-old Bonne admonished her fellow nuns to devote themselves to the service of God and the salvation of souls.
