I think that "Stargirl" becomes an ideal name for Susan because it represents her ability to transcend what is into what should be. The "star" represents something that cannot be held or contained, but rather something towards which one should aspire. The vision of the "star" enlightens us on a dark night and provides light where there is obscurity. It captures our imagination. These are all apt descriptions of Susan, of Stargirl. She is unique and of a level that transcends the town of Mica. She is not conformist bound, and like a star, sticks out from others. Her uniqueness is something that Leo and others can only observe and come to admire, not to be fully grasped. In this, she is representative of the moniker of a "star." Susan's ability to transcend where she is and transform her world into what should be is celestial in its scope and its dimension. This is where her name fits well. Just as the star casts a lasting image in the mind, Leo finds that she has done the same for him at the end of the novel, one in which he has been fundamentally transformed and changed for who she is and what she has inspired him to become. In these examples, the name of "Stargirl" is both appropriate and ideal.