David are you sure you have the correct Esther
in 1841 Esther aged 50 is with Wm Killey 66 ag lab (killey is a diff name from kelly tho often confused - can sometimes be rendered as Gill) - Wm is I think buried Kk German 18450513 aged 79 - in 1851 Esther is found as esther gill widow age 60 born Rushen at Creggan mooar - her son is noted as ag lab