I think we might be on to something

It looks as if Rachel was a Jackson - they must be relatives, mustn't they - or did they find her

on the 1871, they are in Clackmannan
Thomas Marr, 51, land steward & Farms 178 acres for the Lord Burleigh, b. Crawford, Lanarkshire
Rachel Jackson, 43, b. Lesmahagow
Isabella McCadie, 18, general servant, b. Caithness
The 1851 for reference:
Carstairs Mains, Carstairs, Lanarkshire
Thomas Marr, 31, farm servant,b. Crawford, Lanarkshire
Rachel, 25, b. Lesmahagow
In 1881, they are still at Kennet Mains
Gadget