Something is strange here.
1881 census Horton Renfrew
McGREGOR
John, 80, Scotland, widow
Duncan, 44, Ont
Gregor, 41, Ont
John, 40, Ont
Catherine, 38, Ont
Margaret, 35, Ont
This is the same family as on 1851 census.
Next door is:
HART,
Marion, 34
Duncan, 10
William, 10
Archibald, 5
All born Ontario
1871 census McNab Renfrew
HART
Archibald, 26, Scotland
Janet, 28, Scotland
Agnes Fraser, 6, Ont
Archibald, 5, Ont
Hellen Read, 2, Ont
John Wallace, 1/12 March
Marion, 25, Scotland
And the last two entries for the family are:
Duncan McGregor and William McGregor, B July 1870, 9/12
1891 census Horton Renfrew
McGREGOR
Duncan, 52, b Ont
Gregor, 50, Ont
John, 48, Ont
Catherine, 46, sister, Ont
Margaret, 44, sister, Ont
Marion Hart, lodger, 50, Scotland
Wiliam McGregor, 20,lodger, Ont
Duncan ",20, lodger, Ont
Archibald, 15, ", "
Alexander, 8, ", "
Andrew, 8, ", "
I don't think they were married until 1893 as the registration stated. Wonder why they waited so long.
1901 census Horton Renfrew
McGREGOR
Duncan, 7 Mar 1833, 68, farmer
William, 8 July 1872, 28, Ont
Archey, 5 Jan 1878, 23, Ont
Andrew, 15 July 1883, Ont
Alexander, 15 July 1883, Ont
Jannett, McG, domestic, 4 Mar 1890, 10, Scotland, immigrated 1895.
Birth registrations from Ancestry.ca
Duncan and William HART, illegitimate, mother Marion Barr Hart, 20 July 1870.
These dates are 1870 but the rest of the registrations [6] are for 1871.
Those are the only registrations I can find for any of the children.
Marriage:
Thomas Hart, 30, b 1864, s/o Duncan McGregor & Marion Hart, married Mary Wilson, 25 Apr 1894, Renfrew.
Who was he living with on census?
Other marriages are under McGregor
William McGregor s/o Duncan McGregor & Marion Hart married Mary Wilson Hart, 1 May 1907, Renfrew.
Andrew McGregor, 27, s/o as above, married C Norman McNevin 16 May 1910, Renfrew.
The registration definately says Norman. Maybe Norma?
Death:
Marion McGregor died 21 Feb 1900 of heart failure, informant: Duncan McGregor, Renfrew.
Catherine McGregor died 4 May 1907, d/o John McGregor of inflammation of the lungs, informant: Duncan McGregor. Renfew.
Margaret McGregor died 4 Apr 1903 of general debility,inf: Duncan McGregor, Renfrew.
Thomas Hart, 36, died 29 Jan 1899, inflammation of lungs, informant: William Wilson. Renfrew.
1881 census McNab Renfrew
A Thomas Hart, 18, is living with Helen Hart, 74; John 21; Annie 30; Margaret 15; Jeannie F 1.
No relationships are given on this census.
1871 census McNab there is also a Thomas Hart living with Archibald and Hellen Hart.
HOpe this helps some.