I cannot find a direct reference to Marie Claire de Croy, but the Wikipedia article for the House of Croy has this about her, "Marie Claire de Croÿ (1605–1664) was Charles Alexandre's only daughter by his marriage to Princess Yolande of Ligne. As was expected, she married two of her distant cousins, Charles Philippe de Croÿ, Marquess of Renty (in 1627) and then his brother Philippe Francois de Croÿ, Count of Solre (in 1643), in order to preclude the family estates from passing to another family. At the time of her first marriage, Philip III of Spain raised her marquessate of Havré to a dukedom, with her as the first duchess.
By her first marriage, she had two children - Philippe Eugene de Croÿ, Bishop of Valencia and Marie Ferdinande, Marchioness of Renty, the wife of Count Egmond. Her only son by the second marriage, Ferdinand Francois Joseph de Croÿ-Solre, succeeded to the ducal title. Among his children, Charles Antoine Joseph, the 4th Duke of Havré, was killed at Saragossa in 1710; Marie Therese Josephe left children by her marriage to Landgrave Philip of Hesse-Darmstadt; and Jean-Baptiste de Croÿ..."
The House of Croÿ held lands in what is now Belgium, including Havré.
From Molly's photostream on flickr. This photo, taken by Molly, is the best image of this portrait.