I don't have an SO. For the most part I think the answer would be the same for anyone's level of acceptance of you if you look better. One exception might be looking too good too close to home. By this I mean around your SO. if there's issues on her part with her own appearance. By that I mean if you look better in ways she can't and she's not okay with that.
Disclaimer aside, on to the regular question. I think there's a minimum threshold for looks that will get you more acceptance. If you look like a train wreck people are going to have a difficult time with it. If you look and act like you belong and fit in and are dressed appropriately I think that could go a long way towards people feeling more comfortable around you. This also depends on the crowd you are in. Some places are accepting no matter what. Other places may not be accepting at all. Do not Overlook personality. It may not be directly visual and part of your look but it is a big part of how you present and that makes a big difference too. A smile, a winning personality, a friendly demeanor, all add to our presentation to those around us. The more positive and outgoing you are the more responsive people might be.
I think in a similar fashion your overall presentation will help your SO feel more comfortable around you. Always remember it took us a long time to reach the level of comfort we have. Our SO may not have had the same amount of time to get there yet.
