Have some information on James and Mary Nelson....contacted the West Terrace cemetry, after being told by an old aunt of 90..that she thought they were buried there...anyway, got onto their office, and was told that they found a James and Mary Nelson there, but the dates were different to what I had, but not by much..and...that they were buried near both daughters, my aunts, that I also lost. I will give you what I have, dont think it will contravene anything...
James nelson was buried on the 26 May 1930.. Mary Jane was buried on the 26 May 1930

big question here..anyway, they were aged 82, and 83 respectively. The grave location at West Terrace Cemetry is Flinders..on the east side of Path 8 Grave 24.. There is a simple headstone, and I suspect the grave was tidied up about 1966,, as there are white ceramic tiles on the ledger.
I have found a grave immediately to the rear of the above grave described as Flinders, on the west side of path 7 grave 28..This grave contains the remains of Ellen Nelson, who was buried on 1st Nov. 1931 aged 52...and..Mary Jane Nelson (Popsy) who was buried on 26 Oct. 1966 aged 93. I assume this Mary Jane is your Popsy.
1966 ? wonder if the family while attending Popsy's grave tidied up their parents???
I'm guessing that Ellen is the daughter of James and Mary Jane..nee Donovan, who was born on 17 Mar.1877.. She was actually 54, not 52 but women always cheat a bit on age...
Ive also found another Mary Jane Nelson, buried 6 Apr.1915 age 72. Dont think she's yours but one never knows..She was the widow of a Henry Nelson...
Now he has all the dates of my family right, except the ones of James and Mary, but it seems to me that as they are buried very close to the "girls" makes me wonder..
There is a headstone on these graves, and as I cant get there, have asked a cousin, who lives in Adelaide to see if he can, and get a photo, once we know its them...