Assuming she died in Australia and left a will and it went to probate - then yes you can get a copy from the Probate Office in the state where she died, much as you could here.
http://www.jaunay.com/wills.html for starters
The likelihood is is that if there was a will and it went to probate you would have been contacted by now if there was any benefit to you.
Of course it's possible that the will is sitting in a drawer in the derelict house, untouched, if there was no-one to carry out her wishes.