What is the theme in The Game by Diana Wynne Jones?

One major theme in the novel, The Game, is self-discovery. This theme is illustrated through main character, Hailey Foss, who when we first meet her is shy, withdrawn, and unsure. It is only when Hailey is sent away that she escapes her grandmother's constant demeaning statements and blossoms into the self-assured young woman she was meant to be.