Hi did you find any information. I know this is an old post. I am descendant from Avon Roy Mitchell Rowland second wife. And have also been looking for info on the family. And where my half uncle may be. I did find info that Elsie Charlotte may have died in 1980 but can not be certain.

Have you seen this?
No death date, but more info you might want to follow up
Elsie Charlotte Dunn/Rowland
Of Coorow, Carnamah and Three Springs
* Born 1904 in Fremantle, Western Australia. Daughter of Arthur John Wellesley DUNN and Mary Grace GIBSON.
* Married "Locke" Avon Roy Mitchell ROWLAND in Perth July 1936
* After initially residing in Field's Find she and her husband shifted to Carnamah in August 1936
* Attended the Ball after the Carnamah Agricultural Show on 10 Sep 1936 dressed in ivory water-marked taffeta
* Attended the Carnamah Repertory Club's Social including three plays at the Carnamah Hall on Friday 2 Oct 1936
* Her mother, of the Perth suburb of Leederville, spent a holiday staying with them in Carnamah during Nov 1936
* One of the Costume Judges at the Carnamah Girls Club's Masquerade Ball at the Carnamah Hall on 5 Dec 1936
* In 1937 she and her husband were living at 12 Carson Street in the Perth suburb of Victoria Park
* They resided at 253 Heytesbury Road in the Perth suburb of Subiaco 1943-1949
* Herself and her husband had separated by 1954
* In 1954 she was working as a Clerk & Typist and living at 10 Abbotsford Street in the Perth suburb of West Leederville

Lots of info on 'Locke' Avon Roy Mitchell Rowland died of cancer in the Denmark (West Australia) Hospital on 24 Sep 1980

I made a register of all the burials at Denmark cemetery a couple of years ago. At time of compiling, burials were to June 2018.
It is searchable by Date, Grave Number and Alphabetical Order.
Locke is there, but he appears to be the only Rowland.

Anyway, have a look through the lists

OK I have made some progress

John Mitchell Rowland emigrated to Canada, possibly in the 1970s and believe he may have died in 2012. Now know his wife was called Janice Elicia Rowland who was from England, thanks to Mel Constable above who found this. Now to try and trace her, still no clue what happened to Elsie though

Have now established that John did pass away in Canada in 2012, and his mother had emigrated to Canada in the 1980s, where she died. I traced Janice Elicia Rowland to England, so have got somewhere now