I don't know why there aren't more people chiming in on your thread. As I posted earlier I would put off telling the kids for now unless they are starting to ask a lot of questions. Is there a therapist or a psychologist you can consult with? Perhaps the two of you can make an appointment and go together to discuss it.
Your W's behavior is totally typical. I wouldn't be surprised if there was some mid life crisis mixed in with the whole thing. My family interactions have been a lot like yours with my W checking out while I am with the kids.
We had a very small disagreement the other day and she now took all of her jewelry and a bunch of clothes out of the master bedroom and moved them into her room. She also has set herself up in the second bathroom. Her disconnecting more and more has made it even more obvious to my kids that there is a problem. This action coming from someone who says they have the kids best interest at heart...lol.
I feel for you. Just keep detaching and keep the focus on you and not on her. By your posts, you are spending a lot of time looking at what she is doing. It's hard not to but you have take your energy and put it into you and your kids and not into her.
MySitch Me-47 STBXW-41 D-5 S-8 ILYBNILWY-01/08 Want a D- 01/09 Physical Sep-01/10 D filed-06/10 Got 50% custody=09/11 Ride that wave!