Career
King Joseph I of Portugal elevated the Dowager Marchioness to the title and degree of Duchess of Abrantes vitalício (by Royal Decree of 1757) upon her appointment as Her Majesty the Queen"s Maid of Honour (Camareira-Môr (Portuguese)). This was the highest position in the Portuguese court for a lady, and one which her mother previously held. When her mother Duquesa Ana Maria died in 1765, Duquesa Maria Margarida succeeded to her hereditary titles as 4th Marchioness of Abrantes and 10th Countess of Penaguião.