María de Mendoza y Sarmiento, daughter of Juan Hurtado de Mendoza y María de Sarmiento, 3rd Countess of Ribadavia. Maria was the wife of Francisco de los Cobos whom she married in 1522, aged 14. Important arts patron in Valladolid and Avila. She was a lady in waiting to the Empress Isabel of Portugal. Among her friends were Santa Teresa de Avila. She is buried in the chapel of San Salvador in Ubeda, that has a vihuelist decorating one of its portals (16-218)
A brief biography is available online at http://dbe.rah.es/biografias/59783/maria-de-mendoza -- the website of the Real Academia de la Historia.