Yes it can all turn to custard, but the reality is there are thousands doing just what you are asking about.
Even without a sponsor, if she has an Aussie visa she can do monthly trips across the border by car to Oman, which is about a 3 hour round trip, not ideal but very do-able.
Ideally she would get a job, but it can be done. As mentioned elsewhere, just don't piss off your neighbours, especially if they are local. Of course it also helps to refer to her as your wife