This book really brings out the horror that overweight people have to go through. It's like racism: people rarely try to see what is on the inside of them and just see what's on the outside. It's different for school jock Kyle because he used to be one of the those people and it is sweet that he gets to know Rosemary.
Everywhere, there are Bluebirds. You can't walk down the street without seeing one.
Rosemary never tried to get to know anyone and when new girl Kay-Kay is nice to be her (they met in Rosemary's mother's barber shop), she is baffled because Kay-Kay seems to be a perfect fit for the Bluebirds. However, she is not because she is just too nice and to be a Bluebird, you must be super pretty, super popular, and super mean.
Kay-Kay and Rosemary become friends and Kay-Kay is an inspiration for Rosemary. That's what friends do. They inspire us. Rosemary resolves to lose weight, and she'll do whatever it takes one step at a time.