How about separate bank accounts or credit cards? Separated however you like, e.g., a grocery/housekeeping account, a discretionary "hers" account.... For her credit card, you could have a limit that will cover a month's expenditures, e.g., $1000, or whatever works for the two of you.
I once lived with a man who was well off by my standards. He owned properties, a store, etc., and was preparing to retire young. Sometimes when he gave me money for groceries, he'd say, "Don't spend spend too much." I had no idea what this meant; I just spent what he gave me. Mind you, I am an experienced pennypincher, and I could have been very frugal if I knew what was going on. But he was vague, and I didn't think he'd be satisfied with poverty food. After he died, someone dropped hints about his money problems. I had no idea.
Seems to me you need a financial advisor who will tell you what I just told you (and more). Then you can tell your wife that these arrangements are in both your best interests. Or the advisor might have suggestions for how to discuss all this with your wife.
No sense just worrying about money, when there is probably a simple solution. Good luck!