I will send you another two files from SP - the 1911 census for Maryhill has Grace Wilkinson wife aged 40 born Greenock, Renfrew. 4 Children Ellen aged 8, born Greenock, Annie aged 6, born Greenock, John son 3 born Glasgow, Jeanie 1 born Glasgow.
From SP, John William Wilkinson born 1907 in Maryhill, parents listed as Gibson Nettleship Wilkinson, Seaman with the Merchant Service and Grace Wilkinson, maiden name Williams.
Marriage listed as 27th February 1902 London.
I don't know how you check the marriage detail for London.
Good luck
Murphyz