Hello again,
I've been looking into DNA matches the last couple of days, and come up with some interesting (although still vague) findings. In brief, there is clear evidence among the DNA matches of my mother and two of her siblings of links to the Weaverham and Great Budworth areas of Cheshire. This makes me strongly suspect that our ancestor Margaret Harrison of Great Budworth who married Daniel Linacre at Weaverham church in 1751, was from that area.
Two DNA matches in particular are worth looking at, since they allow for triangulation.
"Lyndsay Jones, Nee Ormsby"
descended from Minnie Harrison, b. 1877 in Leftwich, daughter of James Harrison of Lymm & Mary Elizabeth Buckley of Warburton
https://www.ancestry.co.uk/family-tree/tree/66864865/family?cfpid=330106358423"Sharon Harrison"
descended from Henry Leigh Harrison, b. 1866 in Davenham, son of the same James Harrison & Mary Elizabeth Buckley
https://www.ancestry.co.uk/family-tree/tree/170418931/family?cfpid=272219274393I haven't checked the second tree for accuracy, but all the individuals seem to be from the areas of Lymm and Northwich. The earliest Harrison ancestor seems to be William Harrison b. ~1748, m. Ann Dean 1776 in Lymm, d. 1816 in Lymm (aged 68). Going back further is trickier. Lymm is a little way from Weaverham, but in several of the trees I've looked at, there seem to be links between the two areas, for whatever reason.
I should also draw your attention to a record for the baptism of Mary, illegitimate daughter of Margaret Harrison, 07 Apr 1745 at Witton-cum-Tawambrooks (a chapelry of Great Budworth parish).
https://www.findmypast.com/transcript?id=GBPRS%2FB%2F766554082%2F1The abbreviation "st:ra" next to Margaret's name is an unusual one. I really don't know what it could mean.
Finally, here's the will of a certain Thomas Harrison of Little Leigh par. Great Budworth (the part that borders on Weaverham), which may be relevant.
https://www.findmypast.com/transcript?id=GBPRS%2FCHS%2F748091032Please let me know if you have any thoughts or ideas.