This reply may be repeating some information already given

Muriel AULD was AULD by marriage, not birth.
She married
8929/1909
AULD William R
TILSON Muriel
At PETERSHAM
There were two sons before 1914
44528/1911 AULD Robert W
Parents William R & Muriel
At PETERSHAM
17443/1913 AULD John D
Parents William R & Muriel
At PETERSHAM
Who Died
80347/1973 AULD John D
Parents William Robert & Muriel
At NEWCASTLE
The son Robert William lived with Muriel and Robert George GARNER in 1935 at Cardiff and used the name GARNER. He also enlisted for ww2 under the name GARNER
http://www.ww2roll.gov.au/Veteran.aspx?ServiceId=A&VeteranId=415121.
By 1936 Rita Maud is with the family and she uses the name GARNER too, though when she married Robert used his birth name of AULD
6014/1932
AULD Robert W
THOMPSON Rita M
This birth ( as reminder from Wivenhoe, Reply #11).
Parents were Albert Edward and Clara Alberta
21331 / 1914 THOMPSON Rita M
Parents Albert E& Clara A
At Hill End
In 1943, Robert George GARNER is still registered to vote and is living with Robert WILLIAM GARNER and his wife Rita Maud GARNER at Byer Ave Hill End.
So it seems unlikely that the Robert GARNER death at Randwick in 1937 is the husband of Muriel
Though, of course

I am not certain, but Muriel’s husband William Robert , may have lived until 1970 in the Warringah district
Sue