Françoise was descended from French royalty through her paternal grandmother, Charlotte de Brézé, an illegitimate daughter of Charles VII by his mistress Agnès Sorel.

In 1538, Françoise married Robert IV de La Marck, Prince of Sedan and Duke of Bouillon.

[2] Through her mother's high position as King Henry II's mistress, Françoise was appointed Première dame d'honneur to Queen Catherine de' Medici.

As Première dame d'honneur, Françoise supervised the female courtiers, controlled the household's budget, ordered necessary purchases, organized the annual accounts and staff list, and introduced those seeking audience with the Queen.

[4] During her husband's war imprisonment in the Siege of Metz (1553–56) and during the minority of their son Henri Robert (1556–59), Françoise acted as ruler of the Principality of Sedan.