From personal experience (I have been raised in this, currently trying to get out) I believe the best way to go about this tough situation is to, of course show no threat to your wife. I don't know if you know this, but there are women who are regularly praised and presented at our assemblies for circumventing husbands who threatend to withold their children from the "truth". Denying her the ability to take the kids to the meetings does nothing but convince her that Satan is out to ge her and is using you as his pawn.
Even though your reasoning is logical, she is almost bound to look blindly right through it, and to her, what you are saying sounds similar to this: "A nuclear bomb is coming in 15 minutes and there is a safe bunker down the street but I'm not letting you take the kids there, I want them to die with me."
So, yeah, this is what it sounds like when you say that to her, and depending on how "convicted" she is, she is likely to just find ways of getting around you.
Moving on, I think the best way to do this is to spend as much time with your girls as possible- develop a loving accepting bond with them, and as they grow up ask them question to contradic what Mom is teaching. For example, perhaps when the 3 year old is old enough that she's learned bible stories and the like, you could ask her questions like "If God created all animals, why are some made to be bad, like poisonous snakes and frogs?". Promote creativity, and freedom. More importantly, teach them to ask "Why" about everything, no matter how silly the question or the answer. Let them make friends outside of the JW organization; in fact, promote it. If you have friends/family who are not JW's and they have kids yours get along with, let them play together and form a bond.
As they get older, and more into JW teachings bring up more though provoking questions and research, proving the lies in the organization, such as exactly how 1914 is calculated, and why it is wrong, or how if the Governing Body is divinely guided, why they keep changing, sometimes in a backwards fashion, and making huge decisions that will affect their life without even praying. This way, they will hopefully by the time they're old enough to reason and ask questions, they'll realize it's all a fake. If they do plan on getting baptized as they get older, ask them if they're really doing it for Jehovah or because either everyone else is doing it or people keep telling them to. Let them know what will happen if they get baptized, such as how if they ask why too much they might get in trouble, and if they get disassociated they can't really hang with mom when they get older, or anyone else at the hall. Focus on disfellowshipping and disagreement. Show them that it will be hard to ask "why" because of fear.
This all require much planning, research, tact, and work on your part, but if you love your daughters this is a way.
I hope you best on your path in life, and your daughters.
