Hi Ina, I looked through the Queensland microfiche for Martha's death after 1914,both as KELLY and also as MAHER,no result.But did find one of her son's death registrations(William Henry) in Brisbane on 26/3/1942 reg B1942/0555987(only recorded this registration in case you didn't have it).
I found a Funeral notice for Amelia Mary BRUGGY in the SMH dated Saturday 13/6/1931 stating she was to be buried at Rookwood.
Sorry to disappoint you,but your quest continues,I did look at the microfiche up till 1945,but considered it fruitless as Martha would have been over 100 by then.I did take note that there was no Martha MAHER on the 1903 Electoral Roll for Lismore.
Maybe Amy's marriage to Louis LEVY in Sydney in 1905,might tell you whether Martha was still alive,as Amy would have needed permission to marry as she was under 21.
P.S.I apologise for the inclusion of your name as Sue,Sue was the last person I had corresponded with and forgot to turn off.