Thanks,Bill Thomason.
Doing a search on the index of Scotlands People http://www.scotlandspeople.gov.uk does reveal that there were marriages for a Catherine Toye in 1912 and 1916 and one for an Ivie McMillan in 1916, so it is possible that they may have married in Scotland during 1916, but Scotlands People is a pay to view site so you will need to check that out yourself to obtain full details.
There is a birth registered in the North Brierley district of England for a Catherine Toye Dec.1893, 9b, 237 but I cannot see her anywhere in England on the 1901 or 1911 census, so it is possible that she could have moved to Scotland. You would need to purchase a copy of the certificate for more details. The surname TOYE or TOY seems to originate in Ireland and there are more possible results in that direction.