I'm afraid that if I forget about her, probably not possible, her JW beliefs will be confirmation in her mind that I was just another worldly insincere person AND SHE WILL BE PUSHED HOPELESSLY EVEN DEEPER INTO JW. Lousy analogy but it's like trying to dive in to save a drowning person that you really care about.
There is a problem here. You will be trying to pull her out and she will be trying to push you in. Who is going to win?
If you care deeply for her then it may be kinder to let her find her own course, except that will be difficult if you continue with a relationship. Your own desires will override any plans to help her in a more constructive and objective way. That's not good for her or for you.
I personally think that the wisest course is to put the ball in her court. Be upfront and tell her that you would never accept her religion but you know you are right together and that you will support her whole heartedley if she wants to pursue a relationship with you but she needs to make that move, without the constrains of the religion. She can never hold it against you and it will be a deliberate and conscious move on her part.
This is my opinion but I don't think she is your true love. I say this because you are comparing her to your previous two girlfiends. When you find the right person comparing them to anyone else would not even enter your thoughts. You cherish and love that person for who they are. It is difficult to quantify it but it is as if anyone else becomes non existent and losing that person is like losing the most precious gift. From a male perspective this may not be the case and it may not be the perspective of other females.
You are trying to weigh things up from a logical viewpoint which is good. From a logical viewpoint, run and don't turn back.