She was the guiding spirit of the first Fronde, when she brought over Armand, Prince de Conti, her second brother, and her husband to the malcontents, but she failed to attract Conde himself, whose loyalty to the court overthrew the first Fronde.
It was during the first Fronde that she lived at the Hotel de Ville and took the city of Paris as god-mother for the child born to her there.
The second Fronde was largely her work, and in it she played the most prominent part in attracting to the rebels first Conde and later Turenne.
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 Conde, bore her, made her conspicuous.
In reward for his devotion to the court party during the Fronde he obtained many signal favours, and Saint Aignan was raised to a duchy in the peerage of France (duchepairie) in 1663.