I recommend you talk about your concerns with her and with someone you both trust (pastor, counselor, close friend) before you think about getting married, and commit to working through the issues you both have. And, just in case you think people with various conditions can't have successful marriages, remember this: a marriage is made up of two broken people who become more whole with each other. Not the "you complete me" claptrap we've all heard, but each of you will make up half of the new "we" that you create.