Sounds to me like a good opportunity. Since she's willing to go to church with you and supports your new life, maybe she is open to it also. Maybe you can help lead her to Christ. Then your question would be moot.
I think thats a really good point... My life will not be the same and I'm not sure she realizes the implications of that. I will admit although I am now ashamed of it, but we did sleep together on a regular basis and so I guess my worry is that she might THINK she is okay with it now, but realize later on that its not what she signed up for, type of deal. In the long run if we had ever gotten married, I would assume we would want different things for our children if our beliefs were not the same... So I guess in my heart I know I can't date her but its easier said then done... I've had people tell me that she may get saved eventually, or maybe God has someone better for me in store, but that is hard to believe!