2 Isabellas?
1881 Census
Isabella Kirtley, 1871 Black Horse, Durham, Granddaughter of ANN age 73
Possible Daug of John, a Mason in same Census.
Isabella with Parents GEORGE/Jane is with them 1881 Census born c 1873 Lanchester
Black Horse Isabella seems to have married as Amelia Isabella Kirtley 1892 to William Sawdon/Sawden.
1901 Isabella Sawdon is born c 1871 Blackhorse, Durham.