Thank you for all the sound advice.
I have met many of my partners friends (JWs) and they seem very nice people.
I have made attempts to bring up their past teachings and false dates etc. However they just told me that they had recieved new light and quoted a passage from the bible.
Whenever I brought anything else (blood, shunning etc) up they seemed to have answers for everything!
The last time I questioned their teachings with my wife, she arranged for three JWs to come around to my house and "answer" my concerns. I didn't stand a chance and now she feels that she is justified in what she is doing and that it is indeed "the truth"!
Since then I have done a lot more research and feel much better armed, however they make a point of calling when I'm not around (at work etc.) to do the "studies".
I think I will tread lightly with my wife and try to slowly drip feed the information I have learned. My daughter is quite shy and I think that all the attention she has been recieving has turned her head. Maybe if this gradually stops she will see them for what they are.
One final point, my daughter has said at meetings that a 25 year old man, keeps complimenting her on her appearance etc. I have heard that heir is a "shortage" of wives in the JWs as their population is aging. Am I to be worried that she will bcome a target of all the men if she goes deeper into the congregation.
Again, Thanks for all the advice so far.