As her father was the Genovese ambassador to France, Maria Caterina and her mother frequented the salons of Paris and the royal court of Versailles.

Honoré III had previously been the lover of her mother,[3] but wished to marry to provide an heir to his throne, and was attracted by Maria Caterina's beauty.

The Genovese entourage answered that Maria Caterina, was a member of a ruling family of the Republic of Genoa (her uncles, Gian Francesco and Rodolfo Brignole-Sale, held the dogeship in, respectively, 1746–48 and 1762–64).

[3] The ship was therefore stranded offshore for several days, until the predicament was resolved by the couple meeting halfway on a bridge between the boat and the shore.

[3] Maria Caterina attended the French royal court and high society life, but was described as an introverted personality who preferred to sit with the elderly during the balls rather than to dance and who did not use make up, but also considered a great beauty.

[3] Maria Caterina lived in Matignon, where she spent her days with the Prince de Condé, and seldom took part in court life.

[3] Mediation by her mother brought about a temporary reconciliation, but when her father died and left his fortune to his daughter on the condition that her husband should have no access to it, Honoré III threatened to have her sent back to Monaco, upon which Maria Caterina again sought asylum in Le Mans.

[3] Maria Caterina moved in with her lover days after her official separation was approved, and openly lived happily with him in his residence Chateau de Chantilly in Paris.

Her body was laid out in state in one of the rooms and she was buried at the French émigré chapel, St Aloysius Church in Somers Town, London on 4 April.