I spent a year abroad as part of my degree, and I can't think of any immediate pitfalls.
Make sure you know what arrangements are in place for health care, dentistry and pastoral care, but as she will be at a University, not "employed and alone", I'm assuming that all of that will be part of the package.
She will undoubtedly want to travel, so she needs to be clued up about safety in Australia - it is a very wild place indeed once you get beyond the coastal areas. Just wandering off alone into the bush is not a good idea.
Familiarity with the local bugs and beasties is quite important. They aren't as ubiquitous as people like to make out, but they are never far away.
A couple of books are worth reading: Bill Bryson's "Down Under" is hilarious, and really captures the Australian lifestyle and mind-set brilliantly. Another interesting book, if a little dated now, is The Pocket Aussie Fact Book" which gives a good picture of the country. It is out of print, but there are used copies on Amazon.
My favourite fact in it (from a previous edition) is this.
"The world's largest cattle station, 30,028.3 square kilometres, is Strangeray Springs in South Australia. It is almost the same size as Belgium."
Rather puts the Belgians in their place, doesn't it?
Brisbane is a lovely city, and I'm sure she will have a wonderful year out there.