You know my dad told me the actual answer to that question when I was six. He busted out a book with illustrations of a sperm and an egg. People get too embarassed too easily.
How has she's kept it a secret this long while being THIS airheaded?
Also:
"I'm just a member for head count" she says while showing off a full rows of sharp teeth and possibly draconic eyes.
First, mommy and daddy get married. Then, they hold hands. Mommy then eats a lot and gets fat. 9 months later, a stork arrives before mommy and daddy and trades a baby for mommy's fat stomach.