@BonnieB I think you've nailed it. Part 3 is what happened next.
My theory is they go to some temporary accommodation in Byron Bay where they won't be recognised and he convinces her the best way to access the $ is incremental withdrawal and he'll store in safe custody for her and transfer altogether to an account in her new name. She had indicated on her incoming passenger card a duration stay of 8 days, which is til 10 Aug. She has no transport so is reliant on him. Staying in Byron Bay makes sense as she can access banks. He then buys a car and on 11 August he takes her somewhere remote to stay away from their home areas. The car is used to travel into Byron Bay and other areas to continue making withdrawals until the accounts are drained.
Was she coerced/ forced to make the withdrawals, or did she voluntarily do so and then become a victim. Going with the Occam's Razor theory, it's the latter, ie she voluntarily made the withdrawals then became a victim. Maybe he's even sub-consciously told us this with the lies he's told about getting beaten up and robbed.
Does he at this point abandon her (Grafton, Armidale? You stay here I'll be back in a few days). Or does she start to have doubts about him at some stage and confront him? They row and something happens. Or perhaps she wanted to make contact with her family for Owen's birthday and he couldn't let that happen but didn't have an exit plan.