You can always draft a health and/or final wishes directive. I myself see little value in the ceremony of marriage, i view it as an archaic ritual that has little to no place in modern society. But being committed in a loving union is a different matter altogether.....which I think is what you are hoping for.
Stuck1nhead, If you love this woman and wish to spend the rest of your life with her...Then I say go with the flow if it is something that will bring her joy and a sense of security.. If it matters neither one way or the other to you, then enjoy the day's celebrations and make some happy memories with your new life partner.