She gave her husband four children , two of which would survive infancy the future Cosimo III and Francesco Maria de ' Medici , Duke of Rovere and Montefeltro . She gave her husband four children , two of which would survive infancy ; the future Cosimo III , Tuscany 's longest reigning monarch and Francesco Maria , a prince of the Church . At the death of her grandfather Francesco Maria della Rovere she inherited the Duchies of Rovere and Montefeltro which reverted to her second son , Francesco Maria , at her death .