I think that everyone has thoughts like that before they get married. I think that it is completely normal. I was married for almost 3 yrs and am now divorced, and not b/c I wanted it. Be sure that this is what u want, I know that is easier said than done. U never really know what will happen in the future. If u think that there is any possibility that one day u might feel differently about her, try talking to her about it and having a serious conversation about it. Just be honest and tell her how u feel. Even though it might hurt her, she would rather know now than after the fact! That was one major problem in my marriage was a lack of communication, thats the most important thing u can have with someone u choose to spend your life with! Good luck!