I am definitely the "bookkeeper" of the house. I like to budget and account for where each dollar is spent.

If she isn't exceeding her budget, you need to shut your mouth. There is a difference between being careful and being controlling. One is reasonable, the other is not.

When I asked what she needed the cash for, she got defensive and responded "I am tired of being treated like a child! I don't have to justify where I spend our money!"

This is because you are treating her like a child. Amazingly enough, adults resent being treated like children. And when you treat adults like children, they are bound to act out.

But she never did answer my question.

W...T... F! You are not only treating her like a child, you are thinking of her as a child. She is a new mother and you are acting like she needs a daddy.

Marriage is a partnership, just because you like to budget doesn't mean that you get to do all of it, unless you have been given that responsibility as part of an agreement.

So I understand how I can be a little controlling over our finances. But it drives me batty to not know where our money is going.

So, you see that you have a problem. Fix it.

Marriage is a partnership, not a parental concern. Do the budget together, figure out what needs to be saved right off. Figure out what needs to be spent on household items and what can be spent on discretionary spending, then leave it alone. Don't assume that she is going to plow through everything that you have. Which incidentally, as your wife and the mother of your child... is half hers.

My husband demanded a receipt for everything I spent. When he didn't think it was necessary spending, I would not be reimbursed. Every cent was scrutinized and I was berated for things I had done that were considered "wasteful" in his opinion.

He is my ex husband.

Had I noted that this behavior was controlling in the beginning, I might have left a lot sooner. When he started getting more and more controlling and it escalated into abuse.

There are things that you can control and there are things you shouldn't want to control. You wife is in the latter category.