Given the types of disagreements that you are having,

I would suggest that this isn’t a single conversation about how she spends, either spoken or written. Have you considered relationship counseling? If you two want to get married, I think working out these differences now would serve you both very well. Disagreements about money are one of the top three reasons marriages split up. My DH and I have been in marriage counseling for about 18 months now and every session lately we’ve been having aha! moments for why we do what we do. There’s no blame, there’s no guilt, there’s no “you should do things my way, just because”. We are learning who we are, and why we are, and how to change some of the programming we’ve gotten along the way by well-intentioned but also wounded family and friends. I fear that without something deeper like that, you’ll simply continue to have conversations where one or both of you are really frustrated with what the other is doing. Or worse, NOT have conversations. Consider DR the canary in the coal mine – the canary can tell you that something is wrong and needs to be resolved. But the canary can’t fix the problem. I think you would be very well served to seek out some deeper resolutions to how you and she can work together to build a life together. If it’s you and she both trying to impose your own way of doing things on the other, you’ll be having these same conversations for the next 20 years. Been there, done that. Ain’t much fun. But once you start seeing how we bring some unknown assumptions to every decision, and how to change those assumptions, things get a lot easier. Not easy, but easier.