could this be them in 1881? if so, the birth info provided helps.
Dwelling: 26 Palmerston St
Census Place: West Derby, Lancashire, England
Source: FHL Film 1341886 PRO Ref RG11 Piece 3702 Folio 129 Page 37
Marr Age Sex Birthplace
William MC KEAND M 38 M Kirkcudbright, Scotland
Rel: Head
Occ: Police Constable
Janet MC KEAND M 32 F Kirkcudbright, Scotland
Rel: Wife
John Boyes MC KEAND 3 M Liverpool
Rel: Son
William J. MC KEAND 1 M Liverpool
Rel: Son
Alexander MC KEAND U 29 M Kirkcudbright, Scotland
Rel: Brother
Occ: General Labourer
Kircudbright, as far as i know is in Dumfries & Galloway so this looks like a good possible for janet's birth. - did you get her parents names from her marriage cert??
JANET BOYES
Female
Birth: 26 MAY 1848 Dornock, Dumfries, Scotland
Father: WILLIAM BOYES
Mother: JANE BRYSON
i hope this is the family you are looking for.
kind regards,
Lorna.