Louisa Cavendish (1779-1863) (1779–1863) Parents Frances Ponsonby Cornelius O'Callaghan, 1st Baron Lismore Children William Cavendish, 7th Duke of Devonshire Lord George Cavendish Lord Richard Cavendish Siblings Elizabeth O'Callaghan Robert O'Callaghan Mary O'Callaghan George O'Callaghan Cornelius O'Callaghan, 1st Viscount Lismore Partners William Cavendish