I feel your pain ughhhh, I woke up to the cult a couple of years ago and now my wife and I don't talk about much at all anymore. The few times I tried to talk to her about cult stuff she just goes cult defence mode and runs out of the room. The congregation also stepped up to help with the indoctrination of the kids. My problem is dealing with my own feelings and also learning that not only is it a cult but becoming an agnostic. Trying to figure out what to say and teach your kids all the while not getting dfd so your completely out of the picture is not easy.
The religion and the ones in the congregation do what they can to marginalize you so what you say or do is not taken seriously by your kids. The other problem is this is the kids social life, and they have friends their they like. A non believers is really fighting a up hill battle, and I have noticed that when i talk to my oldest son he shuts down mentally a bit. He doesn't want to hear it just want to go along and be part of the group.
I think one of the best things one can do is get your kids doing activities away from the Borg. I have even regretted leaving,thinking that maybe staying in I could be a better shield. I often think that trying to get my kids to become agnostic and living their lives to the fullest maybe to much of a reach. To be a believer and a better more loving Christian may be the only realistic option when they have a devote delusional JW mother.