Hi, You know that the couple are buried in a Wainwright graveyard. and the dates of death.
The Cemetery office may have some information - They will also know the name of the Funeral Home in charge of arrangements. The Funeral home may take the personal information taken for the death registration. They may also see that an obituary is published. This will be held in their files.

A public Library for the area - may have newspapers in their collection. They may offer to search for an obituary - Or - there may be Volunteers at Random Acts of Genealogical Kindness:
http://www.raogk.org/alberta.htm

Searched the Online White Pages Directory MyTelus.com -
http://www.mytelus.com/phonebook/index.do
for the SINGER surname Wainwright Alberta - with 0 results.
There are 82 listings for the SINGER surname in the Province of Alberta.
57 SHAVER surnames in Alberta
There are only 9 KNISLEY surnames in Albeta - perhaps there is a family connection - may be help for your research:

Cheers & Good Luck, Stella