A search of the 1851 census shows the boys were not twins. The census ages imply that Hugh was born in 1848 and Alexander in 1850. There were three daughters, not two. Janet born in 1837, Isabella born in 1841 and Rachel born in 1843/4. Ann Comrie's birthplace is given as Comrie, Perthshire. Her eldest daughter was christened Janet Ewen, suggesting, perhaps, that Ann's maiden name was McEwen?