I think back of my experience growing up as a sibling with a brother who has autism. I always felt protective of my brother but there were a lot of moments of trepidation. We were always worried about Thomas in public or Thomas interacting with people. Because of his autism, we were never sure what would come out of Thomas's mouth. When he was very young, he would do things like crawl under lady's dresses or play with people's arm fat. It was embarrassing and we were always on the look out for what he might do or say. I was always ready at a moment's notice to step in and apologize on his behalf.
However, now that Thomas is a grown man. I find myself still doing it - to an extent. But now Thomas knows what he wants and says what he feels. If I try to step in now, Thomas will correct me and say something along the lines of, "Anna, let me talk!" It is hard to break a habit like that. But Thomas has a right to say what he wants now and he is to the point where he understands the things he says can affect people. He is very appropriate. So I have to work on not wanting to guard everything Thomas says but I don't think I'll ever outgrow the need to protect him!