How long did she support you while you were in school? For however long that was, I think it is fair for you to provide that for her. What she does while receiving spousal support is up to her. If she had not supported you, I'd say tell her she's lucky to get what she got and so long. BUT you two had an agreement that she would support you through school and then you would support her while she worked on her business. She fulfilled her end of the bargain. I don't think your move factors into it at all, you chose to move to another country and anything you left behind was by choice.

Factor the debt into it, ie if she supported you for 3 years at X number per month then you will take the debt into account and subtract the number of months that number equals. So if she supported you 3 years at $500 a month and you have $2000 in debt that's 3 years minus 4 months. You say "seeing kindness as weakness" well first off so far you're only doing what you agreed to do. That's neither a kindness nor a weakness, that's a legal obligation. I don't know how the courts work in Australia, but I think she could easily paint it like you used her to get free rent and expenses while you got a degree where you will be making a lot of money, then once you had that degree you dumped her and moved on and want to not pay her back as you'd agreed. I'm not saying that's what happened, I want to make that really clear!!! Only that I think it would be a compelling story to tell a court. I hope it does not get ugly like that. I'm just trying to look at it from all sides. I hope it works out in a way that you can both feel is fair.