Hi Kylie
This looks to be George's family in 1841 - except where shown, everyone born in the county:
Willm Handley 36, weaver, b. Scotland
Mary Handley 38
George Handley 15, weaver, b. Scotland
Elizth Handley 12, b. Scotland
Thos Handley 9
Wm Handley 6
John Handley 1
Address: Damside, Galashiels, Selkirkshire
Can't easily see William Snr or Mary in 1851, but this looks like Mary in 1861:
Thomas Handley 27, carter, b. Galashiels
Jean Handley 14, sister, b. Darnock Rox.
Mary Handley 61, mother, wool winder, b. Galashiels
Address: Cholmely St, Alva Stirlingshire
There is also a death showing on SP in 1875 for a 75 yrs old Mary HANDLEY, other name Welsh in Selkirk which would be worthwhile you following up on.
In respect of Isabella Atkin, was there a maiden name for her showing in daughter Helen's death cert? There is a death showing in 1857 for an Isabella Aitken, other name Elliot, mother's maiden name Murdie - age 71, in Jedburgh where she shows with Andrew in 1851. If the correct death, it should her include her parents' details if known to the informant, to help you trace her back.
Like you, I cannot see Helen in 1851. George shows as married in his entry with brother William in 1851 as you would expect. Wonder how she has been indexed?
Monica