Oh, go fly a kite!
It's about an emperor in China who has eight children, one of whom is a daughter who is much younger than the rest. She is neglected because she is thought of as insignificant because she is so small and young. She plays by herself a lot and flies kites. Her father gets kidnapped, and nobody else does anything to save him, so she uses her kite flying to save him by flying a rope up to his window, and then he realizes how important she is despite her size and pays a lot more attention to her. At the end it says, "And the emperor never again neglected a person-- whether great or small. And, too, it is said that Djeow Seow ruled after him, as gentle as the wind, and, in her loyalty, as unyielding."
So it shows that even small people who are clever can be helpful. And small people are presumably the audience of this book. And they can make a difference. Everybody can make a difference. Often people who you overlook have talents you'd never expect. And everyone has their own hopes and dreams, regardless of their position in life.