Finally, in 1770, when she was twenty years old, she was allowed to leave the convent and marry her younger cousin, the Duke of Enghien, the son and heir of the Prince of Condé and Charlotte de Rohan. The young duke also held the rank of prince of the blood, however he was descended from a younger branch of the house of Bourbon. The couple married on 20 April 1770 at the palace of Versailles in front of the court. From marriage, she was known as the Duchess of Enghien till the birth of her son two years later.
Her husband was only fourteen at the time. Unfortunately, he tired of her rather quickly after only six months. Despite little contact, their periodic rapprochements eventually allowed her to give birth to a son named Louis Antoine Henri de Bourbon. The scandal of her husband's adultery came out in 1778, and the consequences fell entirely on her shoulders. The couple separated in 1780. As a separated spouse, she was never received at court and was forced to reorganise her life in the gilded solitude of the Château de Chantilly.