Just like jws in general, if you directly confront or challenge their beliefs it pushes them deeper into them. Even if you make a sound point, cognitive dissonance sets in. I starting investigating when a bible student asked me a question I could not answer. While I moved on suffering CD, I kept coming back to that question. A year later I had been reading the Proclaimers book and realized how much had been left out giving the accounts a wrong slant. I investigated my old Divine Purpose book, the 1975 yearbook, and started reading the older books my family had in their library.
But in the end, it was how people treated each other at the KH that convinced me. Why weren't people showing Christian love, and when admitting it wasn't, excusing it because people were imperfect. I was smart enough to see what was deliberate and what was accidental.
So show love to your children, be respectful of their mother even if she is not respectful to you. One person at work told me that it was more effective if we lived a sermon, than preached one.
If they do have questions, answer just that question, perhaps even asking your own question (the point about what age Jesus was baptized was very interesting. I grew up around the WTS and I would have known that answer...It was discussed in 2 study articles in the last year).
I think Steve Hassan's book has some good points about how to talk to them without riling up the cult self.
May things go well, Blondie