Meh, I would think that someone who truly "gets it" would say to themselves "man, getting involved with that kind of bullshit when you're a full on atheist is just going to lead to the relationship's failure eventually." But what do I know?
Seriously though, that's one aspect that I'm not quite sure the implications of. What will her JW family think of your religious views? You were born a JW correct? I would assume they're aware of that. How do you plan on dealing with that? Are they going to expect you in church every week? I don't really know much about JW's, to be honest. What's your girlfriend's views? Is she a true believe, atheist, or somewhere in between? I'm genuinely curious about the dynamics of how that will all fit together.