Medium Sized Momma

Ella: I read in a book that you were a medium sized Momma.
Erin: Oh really? Where did you read that?
Ian: (snickering)
Ella: I read it in a book, that the daddy was a big daddy, the momma was medium, and the baby was small.
Erin: Oh, is that from Goldilocks?
Ella: Yeah.