My old uncle always said ..."big girl big hole , little girl all hole" ....as a steamfitter i call them like pipe ...i would call her a big inch heavy wall ..you can put all kinds of heat to her before the sidewalls break down .
Them thin wall girls just break down after the heat get to 'em....need them hips to hold it together.
Grandma was a delivery nurse for at uhc before it was uhc ..she said she liked the skinny girls the baby just fell out ...