James Green married Elizabeth McMullen on 30.3.1854 at Boveva(gh) Church of Ireland, Co Derry. His address was Burnfoot (parish of Boveva) and Elizabeth’s was Ardinarive (parish aforesaid).
Mary appears to have had a brother William b c 1855. Some of the family had moved to Scotland by the 1861 census and the father James appears to have died in Glasgow in 1884. He was reportedly baptised at Bovevagh Presbyterian church in 1832. His parents are recorded on some trees as Hugh Green and Mary Fowler. (That probably comes from his Scottish death certificate). Brother William appears to have married Ann McIntyre in Scotland in 1875 and then emigrated to Australia sometime soon after his father’s death in 1884. He appears to have died in Australia.
Mary Green's marriage in Scotland to Hugh Wilson was in 1879 not 1881. (GROS ref 644/9/154). You can view all the Scottish certificates on the Scotlandspeople site for a small fee:
https://www.scotlandspeople.gov.uk/