She would have to be in Australia on a substantive visa, e.g. A student visa, working holiday visa. Have you looked into working holiday visa's?? The only thing to be wary of is Immigration don't like you coming to Australia on one visa in order to apply for another. I initially came out on a WHV for a year, to see the country, see where my partner grew up and to generally just have a break after I had finished studying, I had a return flight booked and we were planning on returning to the UK after my visa was up but It didn't take us long after being here to realise that this is where we wanted to be and so we applied for a de facto visa onshore.
Hope this is of some help!!