As for her weight, how big a factor that is has a lot to do with you and how you treat her as well. If she feels that you find her to be a desirable sexual being with a sexually attractive body who genuinely makes you hot, her weight will be far less of a hindrance. This should not be too hard for you to understand. Are there people around whom you feel comfortable with your prosthetic leg and other people with who you feel self-conscious? Part of this is you, but part of it is how they respond to you and what their R with you is like.