As far as I'm aware, teachers need to have completed their NQT year in the UK so that they have some working experience. Technically you are not fullly qualified until you pass your NQT year. However, contact Teaching Australia. Their email is:
overseasquals@teachingaustralia.edu.au
If your OH is teaching secondary maths or science, things may be easier as they are subjects in demand.
Hope this helps
Good luck!