This is her article in thepeerage,com, "Lady Elizabeth Fortescue was born on 10 July 1801. She was the daughter of Hugh Fortescue, 1st Earl Fortescue and Hester Grenville. She married William Reginald Courtenay, 11th Earl of Devon, son of William Courtenay, 10th Earl of Devon and Henrietta Leslie Pepys, on 27 December 1830. She died on 27 January 1867 at age 65 at Powderham Castle, Devon, England. She was buried on 2 February 1867.
Her married name became Courtenay. As a result of her marriage, Lady Elizabeth Fortescue was styled as Countess of Devon on 19 March 1859."