I haven't been able to find much on this couple. Where did you get the information for the marriage as I haven't been able to find one under either Lemmon or Lemon.
I went to family search and found the deaths.
Donald Lemmon
b. July 1, 1886, Emerson, Manitoba
d. 31 May 1979, Vancouver, BC
spouse - Charlotte Hurley
father - George Lemmon
mother - Margaret Collins
Charlotte Lemmon
b. 1887 Llanelly, Wales
d. 12 May 1979, Coquitlam, BC (Part of the Metro Vancouver area)
father - Thomas Hurley
My best suggestion is to contact the Vancouver Public Library to see if they can find some info for you. Most of the larger libraries have an "Ask a Librarian" section. I went to the legacy project but couldn't find an obituary for them. They died within a couple of months of each other and if there weren't any living relatives, they may not have obituaries.
Do you have an approximate date for the birth of the daughter and also her death, whether she married, any information that could help in the search. If you know for sure that she is deceased you can post her name.