I'm married to a man that became a jw a few years ago too. I never, ever let the kids go to the hall!! I said if he was going to bring them to a hell I would bring them to a Catholic, Hindu, Muslim, Baptist, Lutheran, Baihai, etc... you name it, we would investigate the religions of the world. The kids saw the changes in him and didn't want to go anyway. When I found out he was trying to secretly indoctrinate them on a few occasions that was it for me. I began telling them about this organization from unbiblical doctrines to the pedophile issue and everything inbetween. Not preaching at them but they would ask 'what's going on on the board today mom?' And sadly there is always a heartbreaking story somewhere going on so I would tell them that someone is trying to deal with the shunning of family, suicide, murder, or any of the heartbreaking stories.
She should not trust him and do everything she can to keep her kids from ever stepping foot in the hell. Others here will disagree but my kids physical safety (pedophiles in the cong, blood issues) emotional well being (emotional blackmail, psychological problems of jws, etc.) and spiritual well being (they are the most ungodly org I have had the displeasure of experiencing) are my responsibility. I will protect them at all costs.