Mary Stewart, Countess of Traquair (d 1759) Countess of Traquair wife of Charles 4th Earl (d. 1759) Parents Lady Lucy Douglas Robert Maxwell, 4th Earl of Nithsdale Children Charles Stewart, 5th Earl of Traquair Lady Catherine Stewart William Stewart John Stewart, 6th Earl of Traquair Barbara Stewart Robert Stewart Ann Stewart Lady Mary Stewart Lucy Stewart Margaret Stewart Siblings unknown daughter Maxwell William Maxwell, 5th Earl of Nithsdale Partners Charles Stewart, 4th Earl of Traquair