Nurses are definitely in demand. You wont be able to get a job in Sydney or Melbourne straight away, but if you are prepared to move to a remote area like Darwin or Broome, I am sure there are definitely Nursing jobs around.
They only problem I can see is that in those areas there might be no Instructor jobs.
If you get in to a place like Darwin on your wife’s visa, you could always try to get in to the GA up there. To break in to aviation in Oz is not easy. Trust me – I have come the 457 routes!!!!!
If you need any more info PM me!!!