If this helps - re the family Margaret was living with in 1871/81 - I think John Ocheltrie married Jane Appley on 29 Jan 1849 at St. Andrew Church, Newcastle with his father is listed as John Ocheltrie and there is a baptism on 8 Jun 1815 at Newcastle upon Tyne, All Saints for a John Ochiltree with parents John and Margaret.
Possible family in 1841 living at Seaton Deleval all born Northumberlandd with the occupations as Masons matching John Ocheltrie in later census years
John Ocheltrie 55 Mason
Margaret Ocheltrie 55
John Ocheltrie 25 Mason J
Jane Ocheltrie 20
Charles Ocheltrie 20 Mason Ap
Could Jane in 1841 be the mother of
Mary Margaret Jane??

Kay
Added - Probably unrelated but Jane Sharp of about the right age died the year after Margaret was born

SHARP, JANE 45
GRO Ref: 1864 March Qrtr TYNEMOUTH Vol 10B Page 133