There is a Scot-born Wm Duncan ship carpenter m to an Ann Cottier in 1841 with a dau Ann bapt 1834 (also a son George bapt 1837) - he + wife + youngest are at House of Industry (?working) with 3 older children residing with Elizth Callister - I can't find a bapt for a Sarah Ann Duncan in Douglas except for wm's dau Ann