Your counseling session sounds like it went well, and you handled it very well. The less you push, the more you respond to your wifes divorce talk with level headed calm confidence, the more your wifes confusion grows. Now that you are 'accepting' the situation your wife is no longer trying to prove that she is right. That little voice in her head that says 'this may be a mistake' is getting louder. That doesn't mean that voice will ever get loud enough, but you are handling things well, focus on whats right for you.
MikeInMid gives some good advice. Talk to your lawyer. There is actually two different things you want to fight for concerning joint custody. 1 - Joint Physical Custody (meaning you split close to 50% of the time) and 2 - Joint Legal Custody.
Whatever you feel comfortable with and can manage for physical custody is going to be a personal decision. However you should insist on Joint Legal Custody. This means you have to agree on decisions concerning schools, medical treatment, etc.
I would also ask your lawyer what kind of shared custody split you need to have the courts enforce residing close together. If your wife gets primary custody she can decide to move to Alaska next week and you would be SOL. Your only option would be to move to Alaska too. So insist on whatever it takes to make sure this can't happen.
Either way, take care, keep up the fight, and do whatever is right for your and your girls.
