Okay, so if you feel she is going down this route of separating and divorce, you can just let her - i.e. Let her go. You don't have to stop caring - and I don't think you want to. You can still show your S8 and D12 what a good parent is and be solid as a Dad and a Man.
When my WW left with kids. My life improved considerably - immediately. Why? the monster was gone. You know the monster that lays the carpet of eggshells for you, the one that spews, the one that lies, manipulates, is resentful, disrespectful, the one that tears about all you truly care for. That Monster.
I now look at it that, at worst, I have lots of time to have fun and focus on work and me. When I have the kids, its is me and them time. Our relationship is getting stronger. I get the impression, my WW is on the verge of the "oh sh!t, what have I done, scenario". I am going to wait as she goes through this. It will happen I am sure. She is probably so stubborn/lost whatever that perhaps she might not realise or react. But that's fine too. I just need to make me and the kids happy.
Like you I don't know if my W is a WW that pretended to be a W or a W that became and WW and can or can not change back??? You will need to speak to Sandi or someone more qualified on that. I would be very, very interested in the outcome. But from what I read, I think resentment causes the WW character.
Your has different issues to mine. A vet may be able to clarify the impact of these. But looking at a basic W to WW, this is all about disrespect and resentment. Working on your lets them see you (lighthouse stuff). Also, I noticed when my W left, she could no longer see me to focus on her perceived negatives of me.
Just thoughts my friend. Keep reading, don't make any knee jerk reactions. Sleep on it. Walk away from the board for a few days. GAL have fun. Recharge. Be you!!!