What is the theme in One Child by Torey Hayden?

The struggle to save children is the main theme of the book. Torey's class is referred to as "the garbage class". While Torey says that this is an affectionate label, the reader fails to see the love. The truth of the matter is that the school dumps the more severely disabled children into a classroom of their own, cut off from the rest of the school so that no one has to be inconvenienced by their presence.