Do you have an age for Mary Ann from the census? Was she a widow?
Apologies if you already have this information.
Civil registration in Scotland didn't start until 1855, so you will have to find parish records for George. I only found 2 George Gibsons with mother Mary on the IGI born at around the correct time in Scotland.
They were
Birth: 13 JUN 1853
Christening: 30 JUN 1853 Lonmay, Aberdeen, Scotland
Father: GEORGE GIBSON
Mother: MARY HUTCHISON
(There is a sibling Alexander, born 1854. There is an extracted marriage record that may be theirs 22 JAN 1853 Crimond, Aberdeen, Scotland.
There are a number of submitted records for the marriage on the IGI. One of them has George Snr dying in 1904.)
and
Birth: 06 APR 1853 Falkirk, Stirling, Scotland
Father: DAVID GIBSON
Mother: MARY NIMMO
There are 2 records on the IGI for Mary Hutchison born South Shields - rather a strange batch - doesn't specify whether extracted or submitted!!! and doesn't have a film number. It may be the index from a paper file.
Christening: 09 MAY 1824 St Hilda'S, South Shields, Durham, England
Father: John Hutchinson
Mother: Mary Ann Hutchinson
and
Christening: 09 DEC 1821 St Hilda'S, South Shields, Durham, England
Mother: Ann Hutchinson
The only Mary Nimmo in the time frame on the IGI in Durham was born 1830 at Castle Eden.
Trish