Hi there,
When you meet your elderly relative perhaps you may consider asking for any knowledge of any WWI AIF service for either of the two sons of Charles Thomas Edwards ... I notice that among the digitised records at the National Archives of Australia there's a Charles EDWARDS aged 31 on enlistment in March 1916 (born 1884-5 !) His place of birth is recorded as Mt Perry, Qld and his next of kin is his step-brother, whose surname is recorded as DAVIDSON ... Mt Perry is a long way from Windorah and Galway Downs Station but perhaps Charles and Louisa's sons enlisted and their records among the WWI digitised records at the NAA.
The link for records search is :
http://www.naa.gov.au/collection/recordsearch/index.aspx search as a guest
I haven't found the 1949 death indexed at the Qld BDM online .... although I can find it indexed at ancestry under ref 003010 page 647, as Charles Thomas EDWARDS, with parents recorded on that index as Charles Thomas Edwards and Louisa Elizabeth Lawrence. Do you have copy of that certificate ?
https://www.bdm.qld.gov.au/IndexSearch/mainMenuSubmit.m?main_menu=IndexSearch Fingers crossed that your conversation with your elderly relative works out well for both of you

Edit to add Re Louisa Elizabeth, have you considered the 1856 birth registration for Louisa E Lawrence at Bathurst NSW, ref 3253 showing her parents indexed as Charles P and Mary ....
Cheers, JM