Thank you for your reply!
Evidence wise, so far I've got the last 6 months of facebook chat transcripts, records of calls through skype.
I didn't realize that she could travel here after application for a PMV, though. Is that okay to do and won't risk the validity/success of her PMV visa application?
For work, I work full time, at the moment she is between jobs and would be traveling here on a holiday/tourist visa, subclass 600, for 12 months, ideally by which time our visa application is processed for a PMV, or 820, or 309 is processed. I'm fine with her not working here, I earn a decent enough wage and have taken in to account her being here not working with visa limitations.
The major concern however is having her staying here and not having to travel back to the USA, as we'd be moving her things over here in the short term, and she wouldn't have a place to go back to. Hence I'm struggling to see what the best option here is.