Flipper, I was your daughter.
I am my dad's "apple" now. We talk every day and I tell him I love him and hug him and share life with him and his great wife and they love my kids so much.
I am somewhat older than your kids. But young enough that I am at my prime of life. When I started THINKING FOR MYSELF, letting my eyes be opened, I turned to my dad for help. After shunning him since the age of 18, I knew I had to get some help figuring out what to do. The biggest thing I always knew was my dad loved me UNCONDITIONALLY. I KNEW the door was ALWAYS open. Always. That is the most important thing you can do is to never inflict judgement, let them know you are there no matter what.
I was still "shunning" my dad, but I would call him and sob on the phone about my miserable marriage, and other things bothering me about life. He was so supportive. He could have said go fly a kite! But he was patient, baby steps.
It really didnt take long before I had my affairs in order to move on and make drastic changes to my life and I have never looked back in the sense of going back to the JWs.
So all I can say is just keep doing what you are doing. Your kids are young enough where the odds of them finding long term happiness and satisfaction being a JW are low. Also, my mom sounds like your ex wife. Extremely bitter against my dad, like yours is against you. Major attempts at making horrible digs and unwarranted shots at my dad who was a great father. But she was rejected and the perfect family life she had created was upset. I think that can send people over the edge.
If your kids have something that might comprimise their JW stance, a hobby, and interest, something, just think positive about that, and perhaps the tide will change and point them away or weaken their ties to the brainwashing.
You are such a nice person and always so extraordinarily kind to people here. Hoping you can have a happy future, with joy, completeness and in the future a relationship with your kids, and grandkids.