Laura married Louis at the Palais Royal in the French capital on 4 February 1651 and was thus became Duchess of Mercœur. Having married a "legitimised prince of the blood", Laura was allowed the style of "Serene Highness". However, she had a lower rank than that of her cousin the Princess of Conti who had married a legitimate prince. The young duke was instantly enamoured with his wife and his affections were returned. Three sons followed in quick succession the eldest of which being a famous commander in the wars of the Grand Alliance and Spanish Succession. Laura died as a result of childbirth to Jules César, named after his grandfather and the Cardinal, in 1657. Born on 27 January, the Duchess died a fortnight later on 7 February. Buried in Paris, her husband retired from public life to become a cardinal, ensuring his children's upbringing to Laura's sister the Duchess of Bouillon.