The theme of  "Big Girl Small" is that one should not be judged by appearance, but by their actions.  in the beginning, the main character, Judy Lohden, a 3 foot 9 inch midget, is a really talented singer but is made fun of too much for her height so she doesn't even really try.   Chapter 1 in the book describes how she thinks small is such a bad thing and how people torment her for being so small.  It's unfair how people make fun of her even though she is one of the most talented girls in her grade.  Nobody knows that she has such talent because she is so scared at first to even show it to anybody. 

 Big Girl Small article