On page 75 chapter 6, Scout says “It was then, I suppose, that Jem and I first began to part company.” What does she mean by that? What might it foreshadow in her life?

As Jem reaches his puberty years, he begins to broaden his horizons. Much of what he used to do with his little sister does not interest him anymore. Jem has more concern about living up to his father's expectations than playing childish games with Scout. This is the point where Scout realizes that the two now think differently.