I don't talk to my mom about the JW crap unless she brings it up first. The subject just puts her on the defensive anyway, and there is no getting through to her. I'm doing more good by just living a normal life.
This is my tactic now. It hurts her too much when my brother verybally attacks her religion, so I don't do that. Many years ago, she told me that this country has freedom of religion and she gives me that right, but that it applies to her too. I'll admit I was surprised that she said that, but I have respected that ever since. She is 93 and not about to change her religion and I'm not sure I would want her to do that either.
I told her once that we knew things about the WTS that she didn't know. She asked me what we could possibly know that she didn't know. She is well known for being a very serious student of the Bible and the JW religion. So I asked her if she really wanted to know, and she didn't want to take the conversation further. I told her that if she ever wanted to know what we knew, that I would be happy to share with her. I will say she is a very liberal JW, for one who has been one since 1950, and pioneered for about 20 years, married a Gilead graduate, former CO, and city overseer.