I should have seen it coming

Natalie frequently writes me letters and draws me pictures. They don't differ much in what they say or look like. Until yesterday.
She brought me the card and read it to me. "Dear Mom, I love you ever time. And you love me ever time. Thanks for having me. Love, Natawee" Huh, the 'thanks for having me' part is new. Then I opened the card and saw a picture of me and a picture of Natalie. But there was something else that had never been there before. Little squiggly scribbles at the bottom of the circles that is our body/head.
Natalie described the picture for me. "That's you and that's me and I came out of your tummy. And there is your pee-pee, and there is my pee-pee. I came out of your pee-pee!"

Oh god, I'm in trouble with this one.

***There is no photo since you drew it all in yellow and it just doesn't copy well. And I don't really want all of you seeing my pee-pee!