I apologise for the slow reply, but I only just came across your message !
I checked SA deaths to 1915, and could find no definitive deaths for Thomas or Jane - there were many with the details NOT RECORDED !!!
However, is the following an option...???
Firstly, did William Jacob marry Ruth Edwards 1907 Broken Hill ?????
Secondly, Silverton NSW is classed as OUTBACK NSW, and there is a death entry for a Thomas Davis 1895 at Brewarrina NSW, which is nearby. Unfortunately, the parents were listed as unknown.
Thirdly, if Thomas died between 1892 and 1907, Jane may have remarried. She would have been between 34 and 49 years of age. I know this a VERY long shot, but a Jane Evans died in Broken Hill in 1944 to parents Jacob and Mary.
I know this is probably not what you wanted to hear, so I am sorry that I haven't been able to help much this time. If I come across anything more positive, I'll let you know. Kind Regards, Michelle.