Ok heres Alan's birth and marriage records - from FreeBMD
Births Dec 1872
Robertson Alan Camberwell 1d 670
Marriages Sep 1898
Muir Charlotte Georgina D Toxteth Park 8b 422
Robertson Alan Toxteth Park 8b 422
And from IGI we get the marriage details - with a wrong POB?
Husband
Alan Robertson
Birth: 21 OCT 1872 Of, Liverpool, Lancashire, England
Christening:
Marriage: 14 JUL 1898
Death: 08 OCT 1942 Liverpool, Lancashire, England
Burial:
Wife
Charlotte Georgina Dale Muir
Birth: 29 DEC 1867 , , At Sea
Christening:
Marriage: 14 JUL 1898
Death: 30 AUG 1913 Tupelo-Rice, Navarro, Texas
Burial:
Father: James Muir
Mother: Charlotte Maria Ann Jenkins Wilkinson King
Children
Douglas Muir Robertson
Male
Birth: 09 JAN 1900 Liverpool, Lancashire, England
Christening:
Death: 02 OCT 1942
Burial:
Interesting that the wife died in Texas - did the family move there?