Hi Sybil,
Information provided to date (updated in red so all the information is in the one place) seems to be as follows:
The family being sought seems to be:
Parents:
Andrew ROBERTSON (farmer) and Jane (m.s. unknown, born ca 1822 Perthshire Scotland)
Known children:
Janie/Jeanie/JD b ca 1846 Perthshire Scotland
Margaret b ca 1847 Scotland
David b ca 1851 Scotland
Eliza b ca 1853 place unknown
*1874 Eliza ROBERTSON, 21 (address Jay St, Hindpointol, Barrow; father Andrew ROBERTSON, deceased, a farmer) m Daniel (Donald) ALLAN, 32, a seaman from Findhorn, Moray on 25 May at Congregational Chapel, Barrow-in-Furness, Lancashire
*1875 They had a daughter, Jane ALLAN, b Jay St, Hindpointol, Barrow
1875 Eliza (ROBERTSON) ALLAN, 21 (i.e. born ca 1854), died; informant was her mother Jane ROBERTSON
*1881 Moss Side, Lancashire RG 11/3938/95/11
MORISSON (sic) William, Head, 35, b Ireland, Brewer's Clark
Do Margaret, Wife, 34, b Scotland (i.e. b ca 1847)
Do Joseph, Son, 3, b Moss Side
Do Jane B, Daughter, 6m, b Moss Side
ROBERTSON Jane, Mother-in-law, Widow, 59, b Scotland, formerly Farmer's Wife
(From other threads, it seems that the MORRISON family were in Cheshire in 1891 and in Devon in 1891, that Margaret's age was consistent, and that her birthplace was always shown simply as Scotland.)
1881
RG11/3887/69/32
1 Dudley St, Stretford, Lancashire
Jeanie ROBERTSON, Head (Daur), Unmarried, 35, born Scotland, (Formerly Farmer's Daughter)
She is the only person in the household.
This could well be Janie/JD.
*1891
5 Dudley St, Stretford, Lancashire. Jane ROBERTSON widow 69 living on her own means born Scotland Perthshire; daughter J D ROBERTSON age 45, born Scotland Perthshire
*1901
The widowed Jane ROBERTSON, 79, is with her son David ROBERTSON and family. Bishop St (RG/13 3709.) Jane Robertson 79 Widow Born Scotland Living on her own Means; Daughter Janie ROBERTSON 55 single, born Scotland; Son David ROBERTSON 50 married, born Scotland; Grandson Joseph ROBERTSON 18, single
Some questions.
#Can you provide the details of the 1901 census entry - especially the age and birthplace of David.
#Do you have David on earlier censuses (just in case he was born in Scotland and there is a more precise birthplace).
#I note that the daughter of Margaret (ROBERTSON) MORRISON was listed as Jane B in the 1881 census. I take it that she is the Jane Barclay MORRISON, b Dec qtr 1880, Chorlton. Do you know whether 'Barclay' comes from William's side or might it be a clue to Margaret's side.
#Do you have Margaret's MC and David's MC - for information on where the marriages took place, and whether they give father as Andrew, and occupation as farmer, and whether he was deceased.
#Do you have the full names of David's children in case there are family names used as middle names (I note from other threads that Jane is the only one of Margaret's children in censuses with a middle name which seems to be a family name.)
#Are there any possible widowed Jane ROBERTSONs age ca 69 (age was 59 in 1881 and 79 in 1901), b Scotland, anywhere in England or Scotland who might be possibilities and might help in the search.
Good luck,
JAP