If nothing else, budget out some spending money to factor in what she buys. Open up a second checking account, direct deposit the money into that account. She can spend from there, but not pillage the main account.
But again, that's "if nothing else" because it's hard to do one thing when your spouse isn't on board (and doing things that actively work against it). Also, keep in mind this advice comes from a 34 year old w/ no kids, and who doesn't combine money with a SO, and who's SO works full time. I say keep that in mind, because while I think it's a good "if nothing else" idea, it might come across as giving her an allowance, which seems pretty dated.