At Mary's Source is the fifth volume of the interviews given by Yvonne Trubert to the Book of Invitation to Life. Through themes such as Maternity, Education, Wisdom and Mary, the mother of Christ, Yvonne Trubert proposes consecrated reflection to each one of these subjects, going from the most mundane preoccupation to the subtlest questions about the place of humanity in the cosmos. Above all, two subjects predominate : the power of love and the divine presence. Yvonnes Trubert invites each living being to understand that, « everyone must be conscious that he or she is loved, that he or she has the right to live, and that he or she has an extraordinary past and a fabulous future. »
From 1976 onward, Yvonnes Trubert consecrated her life to others by listening to them and consoling them. In 1983, she founded the association Invitation to Life.