I don't have a lot to add, but I just wanted to say hello and say how incredibly painful this sounds to me. I can't even imagine splitting my two children up. They deserve to have at least that much stability. It sounds all so painful.
As to your kids, research shows that if kids have ONE adult in their lives who has their back no matter what, they are quite likely to be resilient. You don't need your W to be that ONE if you are going to be it. I mean, more is better and no doubt that this is painful, but we move through trauma when we know we are loved. So much pain for all of them trying to sort out why one kid and not the other, ouch.
I wish I had more to offer, other than wow and ouch and your W sounds like she's lost her marbles. I hope, for your sake and the young ones, you can keep your marbles together as you sort this out. Come and vent and journal and we will read and support where we can.
BD#1: "marriage is over" 9/14/2016 H in basement 24/7 with EX/OM BD#2: 3/20/2017 I plan to move out "soon" I LRT me: 42, H, 41, EX/OM, 37 D 10, Son 7 M to H = 20 years EX/OM moved in 10 years ago