Here is a great little assessment of the “wisdom” of marriage partners having separate financial accounts. A snippet:
The way I see it, there are no individual expenses; that ended when 130 of our nearest and dearest watched us swear to love, honor and cherish. If Peter had no income at all, he would still need clothes, haircuts, and the occasional night out with friends; likewise with me. That’s one of the things we both signed on to provide the other person. So who cares whose income it comes out of?
My experience with marriages in trouble suggests that her concerns are absolutely correct.