Searching for descendants/immediate family members of Walter (Wally) and Alexandra (Sandra) Rennick

Backstory: my late parents were best friends with the Rennicks - Fort Frances/Atikokan/Dryden area, early-to-mid 50s, when we moved out of the area. They'd kept in touch over the years, though I have no recollection of meeting them. Three kids: Robert (Robbie), Kent, & Karen Kristine; they'd be in their mid-late 60s. 

Efforts to date: I've only been able to track a partial obit/tribute for Walter, for 8 Feb 2019, in the Perth (Lanark County) area. The tribute mentioned they had a farm(?) in Little Britain and a mention of step-grandkids. I'm guessing they'd been there a while  - hence my reaching out to the community. No mention of Sandra, so perhaps she's still alive/in LTC? The funeral home responsible for the arrangements was shut down shortly after, and no obit exists that I can find: both would have been invaluable resources, in that family relations/locations are usually included. 

Request: I have several Rennick family photos that were in my late mother's collection, dating from the early 50s - 90s; I'd very much like to get these back to the Rennick "kids." I've had success tracking down and returning other vintage family/friends' photos, but various searches have come up with nada re: Rennick.

Any lead on their whereabouts would be greatly appreciated! I'm in Eastern Ontario.