She was the royal governess of King Louis XIII of France and his siblings.
She was appointed royal governess to the children of King Henry IV of France.
[1] She was given the responsibility for the king's children with Queen Maria of Medici, as well as for the children of the king with his mistresses, who were raised together.
She was referred to as "Mamangat" by her royal charges, who corresponded with her as adults.
[2] Her daughter Jeanne de Harlay (later Jeanne de Saint George) became a playmate and sub-governess of the royal children, who called her "Mamie", and was later lady-in-waiting and correspondent to Henrietta Maria and, finally, appointed governess to Anne Marie Louise d'Orléans, Duchess of Montpensier.