It’s quite a coincidence that your wife pulled this on you right after you closed on a new home. I’ve learned over time that marriage should just be abolished , ( I can give you why I feel this way elsewhere ).
It appears like your situation is headed for divorce. What makes your situation worse than mine is the children involved, which makes it MUCH harder to deal with. If you look closely you’ll probably discover that this just didn’t come out of “ nowhere “. Think of incidents or things said that you maybe didn’t interpret correctly. They give clues that lead up to it. My advice , from personal experience , would be to stop trying to reconcile and start thinking about how your going to move forward. You need to get in survival mode because things can get very nasty. Also sounds like she has personal issues related to her child and has to face them. The only thing I would try is couples therapy. If that goes nowhere, ( considering that she even agrees to go ) , then therapy for yourself. If you have a good friend that you can confide in consider yourself blessed.
Best of luck to you......