Katy,
The fact that your daughter came home for christmas "like normal" I think you said, shows she's still in the early stages of indoctrination. That's good. She isn't yet unreasoning and accepting of all she's told. You must decide if you need to intercept what she's being taught or not. If you don't, you run the risk of her deciding, eventually, that you are not good association for her or her daughter. You also run the risk of her only talking about religion in your presence. Now, you can do the same to her, which would be a mistake and I assume not your motive.
I can't tell you exactly what to do because I dont know your daughter, but you do. I would suggest that you lay off the heavy pressure and just drop questions. For me, the most obvious are the most powerful.
If I dont become a Jehovah's Witness, what will happen to me and all our family? Do I have to be a Witness to be saved by Jehovah? Will he cause my eyes to rot out of my head as I stand or will fiery hail crush my skull?
Asking these questions in direct, non sarcastic ways, made me think.
Why would Jehovah do such a thing? If she says well, all the wicked will suffer this, then ask, Will I be considered wicked and have my skull crushed? If you agree that there is no fiery hell, you could say, "I agree that a loving God would never torment people forever in fire, but would he burn men, women and children alive until they die by fire from heaven? What's the difference?
I would ask, thier question: they often ask, "If you had a child that disobeyed you, would you hold thier hand in an open flame for a week? If you did, what would the neighbor's think? Would they say you were a loving Father or mother? Therefore, Jehovah wouldn't do it to us in a firey hell. SO THEN: If you had a child that disobeyed you would you take them into the street and poor gasoline on them and light them on fire and watch them be consumed before you? If the police came would telling them that "Its way shorter than eternity" make it ok? What would that make you if you did it to 6 billion people at once?
What about your baby neices and nephews, (if there are any. OR any other appropriate child relative.) Instead of presenting anything new, make her defend what she is being taught and holds to.
Keep it low key. The heavy doctrine stuff can come in time.
Good luck,
W.Once