Sierra: "If you've already had your baby, how come you're still fat?"
Me: Smiling patiently... "Well, I actually weigh a tiny bit less than when I got pregnant, but it takes a while for your tummy to get back to size."
Sierra: "Oh...Because you look like you did when you were a little bit pregnant. I hope it doesn't take this long for MY tummy to go down after I have a baby."
I explain all the things that increase your weight when you are pregnant, and then add that most women also add body fat.
Sierra: "Gross! So you might always be fat?!? That would be embarrassing!"