You shouldn't let her become more distant. Almost everybody faces his kind of situation. You guys could work out the distance. It won't be same and you guys would get busy with your separate lives but it doesn't mean that it should affect your friendship with her. As for you ignoring her bcoz of your relationship that's also happens with a lot of people. Talk to her and try to be positive. If you move on with your lives with that kind of thinking then it could affect your relationship negatively. No need to force it. Try to manage as best as you both can and ultimately its all about understanding and trust.