southportgirl,
Having Agnes's date of birth is a big help.
If that is her father in the WWI attestation papers, and her parents in the marriage record, then it seems possible that Agnes was born in London, Ontario.
It appears that Ontario birth records on FamilySearch.org only go up to 1912 and on Ancestry up to 1913. However, birth records go up to 1917 at the Archives of Ontario.
http://www.archives.gov.on.ca/en/tracing/the_records.aspx1) You could wait a year and see what gets added to Ancestry and/or FamilySearch.
2) You could post a look-up request on the Canada board asking if anyone is going to the Archives of Ontario (it's in Toronto) and if they'd be willing to look up Agnes's birth record for you. Include her mother's maiden name.
The marriage record states that the groom was Presbyterian and the bride was Church of Ireland; does that mean Anglican? It also says they were married by a Baptist minister. So it's hard to narrow down where Agnes might have been baptized (if she was baptized as an infant).
What kind of church was Agnes baptized in when she was 14?
3) You could search online and see if it is possible to request a search for Agnes's baptism from the appropriate church archives for London, Ontario.
Good luck!
Josephine
