Pencil thin Barbie dolls

My family is made up of pencil-thin, pretty Barbie dolls. They have had two kids and four kids. And they are still a size 4-6. What's up with that?

It's depressing. So they are pretty... And thin... Have nice houses... And are happily married.

How do they stay so thin? I an envious of them and how they look.

If only I could be even thin and pretty...