Stevepill, you seem to be a little indecisive here.
What do you want in the relationship?
What are you worried about?
Stand your ground, man up.
JW is not just a religion, it is an identity. It is based on fear, guilt, promises never realized, it runs deep. Your girlfriend clearly struggles with the JW identity. Whether she is living it or not, it is her foundation and until that foundation is recognized as flawed by her, anything else in her life is built upon it.
She has two failed marriages as it is. She needs to address her issues and until she is willing to take an honest look at her foundation, she will only address symptoms. Major events in life will cause her to reflect on the indoctrination and may very well drive her back to the religion at some time. Even if it doesn't, she will always have difficulties if she believes that it might possibly be The Truth.
When she has her own kids, even if she was willing to sacrifice her own life and ignore her faith, she won't be willing to let her kids die at Armageddon. If she believes the religion, she will want to return to it because in her mind not doing so would be a death sentence to her children.