No, they don't know. My son is 5 and my daughter is 10. They know mommy and daddy are working on getting better with each other. Well, that's what they were told long ago. But my WW is only working on herself, so now it's...I am living in Minneapolis because I'm looking for work.
Today it hit me the kids are blaming themselves (which children typically do in situations like mine). They have been very emotional today and when if they would make a mistake, I would correct them (like I normally do, normal tone of voice,etc.) but this time they would respond with, "I'm sorry! , I'm sorry!"; "It's all my fault!" in response to what they had done. I plan to tell my wife this the next time we talk. She is completely in the line of belief that separation and divorce can have happy, well-adjusted kids. I've told her we can try to minimize it, but the kids will be faced with so many more challenges that they normally wouldn't have to face if it wasn't for this separation. She'll probably start sending more gifts to try to correct the behavior or possibly blame me? LOL Whatever. I've told family on both sides I am going to need their help now more than ever because of their reactions to my wife's ABANDONMENT.

You should tell your children the truth. They need to know. And you don't need to tell your wife that you are telling them. You should sit them down TODAY, and tell them the TRUTH.

It does them no good to be lied to, and you do your WW no good by hiding her secret.