She was born in the prison of the Château of Vincennes into which her father and mother had been thrown for opposition to Concino Concini, the favourite of Marie de' Medici, who was then regent during the minority of Louis XIII.

Her early years were clouded by the execution of Henri of Montmorency, her mother's only brother, for intriguing against Richelieu in 1632, and that of her mother's cousin the Count François de Montmorency-Bouteville for duelling in 1635; but her parents made their peace with Richelieu, and being introduced into society in 1635 she soon became one of the stars of the Hôtel de Rambouillet, at that time the center of all that was learned, witty, and gay in France.

In 1642, she was married to Henri II d'Orléans, Duke of Longueville, governor of Normandy, a widower twice her age (his first wife Louise de Bourbon had died in 1637).

In 1646, she accompanied her husband to Münster, where he was sent by Mazarin as chief envoy, and where she charmed the German diplomats who were negotiating the treaty of Westphalia and was addressed as the "goddess of peace and concord".

In the last year of the war, she was accompanied into Aquitaine by the Duke of Nemours, an intimacy which gave La Rochefoucauld an excuse for abandoning her, and to immediately return to his former mistress the duchesse de Chevreuse.

[1] There she became more and more Jansenist in opinion, and her piety and the remembrance of her influence during the disastrous days of the Fronde, and above all the love her brother, the great Condé, bore her, made her conspicuous.