What does your brother want? Does he want to go to therapy? Does he want to talk about stuttering? I’d start there. I don’t stutter, but my husband does. I’ve seen his family (long story but he went into foster care at 12 and was lucky to be placed with amazing people who he considers his parents) be really awesome allies to him. I think what most helped him was that it was never about “How can we get M to stop stuttering?” It was always, “M stutters, how do we support him?” Your brother may stutter the rest of his life, and that would be okay. It’s good to think about things that might be tough for him, like high school. But, I think it might be helpful to change the focus from so how can he stutter less to so how can you support him/advocate for him to make those situations easier? Don’t be scared for him, or feel sorry for him. You can be the person who encourages him that his stutter is just a thing he does sometimes and doesn’t need to define or restrict his life. Just being a good sister and friend, and showing that you don’t care that he stutters and value what he has to say anyways, can by itself be a great support. My husband has told me that the difference for him between school being tough and then going home to his bio mom where it was also hard and chaotic and then school being tough but going home to a place where he felt accepted and loved and safe was huge.