clay ... you would be wise to listen to the advice here. I don't agree with the same reasoning but in the end you will likely suffer big time if you keep pursuing this girl.
If she has grown up in the beliefs of Jehovah's Witnesses, it will likely stay with her for life. Even if she leaves her beliefs for you or any other reason there is a very good chance that somewhere down the road she will return to her beliefs. It is more than a religion .. it is a way of life.
Do yourself and her a favor and move on.