After her parents died of smallpox in 1724 in Paris, she and her brothers lived at Versailles with their uncle, Hercule Mériadec de Rohan, Prince of Guéméné.
On 4 June 1736,[1] Marie Louise married Prince Gaston Jean Baptiste de Lorraine, Count of Marsan and Walhaim, (1721–1743).
When Madame de Tallard died in 1754, Marie Louise was appointed to her aunt's position as royal governess and took over the care of Louis XV's ten children.
[4] Madame de Marsan remained as governess for twenty-two years, and taught the future Louis XVI[4] and his siblings.
[4] She took a progressive initiative when engaging the Marquise de la Ferté Imbault, daughter of Madame Geoffrin, to educate the princesses in philosophy, a subject normally only taught to boys at that time.
[4] In 1785, she unsuccessfully appealed on her knees to the queen, despite her dislike for the latter, to show mercy to her nephew the cardinal de Rohan, who was implicated in the famous Affair of the Diamond Necklace.