I remember that all the girls in junior high had to go in to see the nurse to be tested for spine scoliosis. I don't know why it seems to be much more common in girls.
One of my daughter's friends had scoliosis and did wear a brace for a while. But she also had physical therapy to help correct it.
If a child of eight to nine years was diagnosed with it, I think that it would be difficult to get the child to do daily exercise. I don't know how you would convince them of the importance of doing the prescribed exercises.