Do it yourself. The comments above are mostly piffle.
Don't need to fund her account. That is a scam perpetuated by agents.
I have done this successfully three times by myself. First time around I decided to do it myself after talking to an agent in Bangkok who said we would have to create a fake company for her and then a fake bank account showing income from the company....blah...blah...blah.
Screw that I thought, and just did it myself. No dramas whatsoever.
I recall also on the girls visa application I wrote occupation as rice farmer on all three occasions.
Yes a lot of paperwork but you can put it together in a morning.
Make sure you include a sworn statutory declaration regarding your financial support while she is with you in Australia. Also state that you will have comprehensive travel insurance for the duration of her visit. And that you will ensure that she does not work or overstay her visa.
I could dig up one of my old declarations...maybe if you interested in a copy.