1) Marriage. After being legally married, a temporary visa can be applied for the female to allow her to stay temporarily in Australia for 2 year. During the time, she can work and study ( but studies will not be subsidised, ie she pays international fees). After 2 years, the female can then apply for permanent residency, which will take a further 3-8 months of waiting. All in all, the commitment is 24+ 8 months.
2) De-facto relationship. A couple has to stay together for 12 months and demostrate evidence they will continue their life together. The PR holder/citizen can then proceed to apply for PR for the non PR holder.