Born c. 1700–1702,[a] in Versailles, Angélique was the illegitimate daughter of Philippe II, Duke of Orléans and his mistress, Christine Antoinette Charlotte Desmares (1682–1753), a beautiful actress (tragedienne) of the Théâtre-Français.

Charlotte Desmares was a niece of Marie Champmeslé and one of the many mistresses of the then Duke of Chartres, around the time their daughter was born.

Born in 1702 was another illegitimate child of the duke, Jean Philippe d'Orléans, by a lady-in-waiting, Madame d'Argenton.

Angélique's half-brother was legitimised in 1706, whereas Angélique was neither acknowledged nor recognized,[3] although Madame du Prat erroneously states in her memoirs that she was recognized on 22 April 1722, the same day as the Abbé de Saint-Albin, another illegitimate son of the Duke of Orléans by his mistress Florence Pellerin.

Shortly upon her birth, Froissy was separated from her mother into the Duke of Chartres' care; she was raised at the Palais-Royal and the Abbey of Saint Denis.