Hi fsoduck,
I guess you have tried with SET already? If not then getting your point heard SET helps. Most likely this is not a rationale problem but one of fear and trust. You don't trust her and in turn she does not trust you. Rebuilding trust takes time - it is based on delivered behavior not talk. Trying to force a rationale argument is likely invalidating considering that she has strong emotions tied to money.
Her behavior is not rational and you are right in suspecting fear etc... The best - although limited - way to handle this is validation. From what you wrote it sounds like she is constantly extremely stressed/distressed - the car incident is a sign of it. You can't validate her enough, she needs plenty.
Boundaries are another part of the solution. Paying her CC - why? If she defaults - her problem isn't it? Her car the same - if she can't drive it is her problem. She may neglect the breaks but have you noticed how fear driven she is - a small reminder in SET form may be all that is needed to get that fixed in no time.
Also, she is insisting we "consolidate" accounts. I have told her I am willing to do so, but that means she also needs to deposit her check into our joint account. She says no. She then calls me from work every day asking for money to buy lunch or snacks, but I refuse to give it to her. On principle, she is working and should be able to cover these things herself. However, she puts it on her credit card and then expects me to pay it.
Consolidating accounts is not a good idea as it weakens boundaries and just leads to more conflicts. Constant calls from her to hassle you - that needs boundaries too. You could use SET to explain to her that this is distracting and you will not listen to it anymore. It is her problem to feed herself now or go hungry. Then when she calls and starts politely but firmly end the call. As with all boundaries she won't like it and there will be an extinction burst. Looks like you are starting to get more serious about boundaries now so it would be a good time to review this material and plan properly. You don't want to have too many boundary related conflicts ongoing at a time but you want to be firm in each and every one of them. This is not about winning fights this is about making sure you are getting the minimum respect that you deserve. Conversely she is quite sensitive when it comes to boundary crossing (car incident) so where possible show her respect too.
Mortgage - not sure what a fair solution would look like as there are questions like deed, equity and the whole legal status of your marriage finances may need considering. If I can't fully understand it I would wonder whether you would cheat me if there is no trust. So trust and understanding both are required for her to sign up to paying a share. Not sure how to speed that up very much. A first step may be developing a full understanding of the financial mechanics - the legal board may be a first stop and maybe a professional advisor that is seen as neutral could be another step. There is however no point in pushing it as long as she is constantly somewhat dysregulated and a minimum level of calm, mutual respect and trust has be re-established.
