Betty is a clown that has the hability to restructure her own body to be more skinny and light, to apper more appealing to children and parents,it has some problems...her legs doesn't really shrink down, its only her torso...so you can imagine the proportions.

She can Restructure her body with the medallion of her chest, one pull and is skinny,another pull and her will be fat again.

The normal body of Betty is the fat one,that is why the legs cause problems to shrink down. She only let herself out with her normal body on accident, or when another people pull the medallion.