Lizzie: "Mommy, I want to have a baby. Now."
Me: "Oh. Wow." (thinking fast) "Well, you have some babies upstairs sleeping in their crib. Why don't you get one of those to play with?"
Lizzie: "No, I want a real baby."
Me: "Well...that's great. But you're going to have to wait a while. If you decide to get married when you grow up, maybe you and your husband will be able to have a baby."
Lizzie: "You don't understand. I want five babies. Not one plus one equals two. Five."
Me: "That's a lot of babies, Lizzie. I guess that means I'll get to be a grandma."
Lizzie: "Do you mean you'll be my grandma? I have grandma already. Want you to be my mommy. Be my mooommmmy!"
Then there were tears. Then I explained (again) how family relationships work!