William Sinclair, 3rd Lord Sinclair abt. 1437 - 1487 (1437–1487) Parents William Sinclair, 1st Earl of Caithness Lady Elizabeth Douglas Children Sir William Sinclair, Laird of Warsetter, Newburgh and Tolhobe Henry Sinclair, 4th Lord Sinclair Siblings William Sinclair, 2nd Earl of Caithness Robert Sinclair Alexander Sinclair Mariot Sinclair Susan Sinclair Arthur Sinclair Katherine Sinclair Lady Elizabeth Sinclair George Sinclair Sir David Sinclair Eleanor Sinclair Oliver St Clair, 12th Baron of Roslin Catherine Sinclair Lady Margaret Stewart Partners Christina Leslie