From Wikipedia. Her daughter Maria Beatrice was briefly Queen of England before Parliament turned out her husband, James II. Laura's Wikipedia article is here.
This is the standard portrait of the oldest Mazzarinette - but not as old as her Renaissance-style dress would suggest. She appears to be wearing coral jewelry.
Keywords: Martinozzi family, Este family, Duchess, curly coiffure, hair jewelry, jacket, high neckline, collar, chemise, under-collar, rolled sleeves, necklace, draped necklace, earrings, brooch