Mary FitzWilliam (1707-1769) (1707–1769) Parents Frances Shelley Richard FitzWilliam, 5th Viscount FitzWilliam Children Henry Herbert, 10th Earl of Pembroke Siblings John Fitzwilliam Frances FitzWilliam Richard FitzWilliam, 6th Viscount FitzWilliam Partners Henry Herbert, 9th Earl of Pembroke