1851 census has the family at Ballahaug, Andeas

Andreas, District 1, schedule 53
John Christian, head, married, 43, aricultural labourer, Andreas
Elizabeth, wife, married, 41, Jurby
Margaret, daughter, unmarried, 26, Andreas
Elizabeth, daughter, 8, scholar, Bride
Robert, son, 5, Andreas
Thomas Brew, grandson, 2, Andreas
John Brew, grandson, 1 month Andreas

This seems to confirm and early marriage for both parties (17/15) and your 1810 birth.