I know this is not comforting. I am in the same position with two children we adopted. For me, it is a two edged sword. I hate to say this, but the youngest boy would be unbearable if he didn't have the strict control and his mom taking care of that end of things. Family life is quite manageable right now. Because my mom has stopped talking to me, I often will ask the kids when the opportunity arises, "How would you feel if your mom stopped talking to you? It wouldn't be loving would it? Well, your grandma stopped talking to me because I am not a Jehovah's witness. But I will always talk to you, because the Bible tells us to show love."
But now, I worry that while things are calm now, (sorry, this is due to the cult), how will they feel later when they discover why dad is not a witness? I fear that they will despise there mom. One reason for that, is that I feel that my wife knows that I am not messed up. I have shared TTATT in the very early part of my departure. So, my plan is to ask her, "how will she feel when the kids learn what I know later down the road? You may be sincere, but kids will not see it that way. Do you want them to harbor bad feelings towards you?"
I am sorry that I am a straight shooter in my approach. That is not the way for some. But the pain will come now or later. I would rather get it over with. And while it would be nice to get the kids out now while they are still little, some things you can't control. Worrying will not fix it. But if you get them out later as teenagers, that is better than nothing. I know my 20 year old is very happy I saved him at 19.
I wanted to add, that I don't feel, regardless of what I believe, that simply showing the kids science and evolution will change things. Many kids will not connect the dots. Simply, because these things are "bad". But kids do see hypocrisy. They understand concepts of love. They do know what a lie is in the context of the organization.