You're going to want to get your own lawyer soon because she's obviously squirreling away money for future use. This is not helping your situation either because you need to pay bills with this money.
Can you talk to her and tell her she is leaving you without money for the bills?
I'm recommending a lawyer because if you decide to split, or if she decides, she's already hiding assets and you'll have a tough time locating them. You want to get her to stop it now, and a lawyer can help you with that.
She's allowed to do what she wants with her money. In fact, some couples have separate accounts for everything. That being said, she knows she's putting you in a really bad situation and it's apparent that she doesn't care if she is doing that. I'm really sorry this is happening. It's awful, and I understand your frustration. You need to figure if you want to go forward as a married couple or if you can't anymore because she doesn't trust you and now you have good reason not to trust her.
If she's a co-signer, she is responsible for the loans too, so she can't just walk away from them. However, your credit rating is going to take a nosedive unless something is done to stop this right away. If you file for a legal separation or a divorce, your lawyer can make a motion for an injunction, getting her to stop moving money around. The judge may even freeze assets so that she can't do that and so that she pays her share of the bills.
She's supposed to be paying the bills with you but at this point, she is doing what she wants. The only way you're going to be able to stop her is to get an injunction against her from moving her assets. It's unlikely that you are going to get this without filing for at least a separation.
Also, as far as the W2 is concerned, she does not have to show that to you. During a separation or divorce action, she MUST show that to you. It's called discovery, and you're allowed to find out how much she makes.
I'm so sorry that you're going through this but I hope this helps you.
I can also find lawyers for you if you'd like. You can also request that she pay your legal fees!
Does this answer your question?