On a beautiful sunny day like today, why not suddenly talk about skin color, race, and adoption?:
S: I have sunscreen on my skin so it doesn't burn and turn red or turn brown or turn dark like K___ and N___ (her friends at preschool).
Laura: You'll never have dark skin like K___ and N___ because their parents have skin that color.
S: No, they don't, because when their parents pick them up every day, their skin is light colored.
Laura: That's because their parents adopted them. They have two sets of parents...
Sophia and Laura continue to talk about other adopted friends and their parents' skin colors for a bit, then Laura informs her that Daddy's skin color is darker than Grandpa's because Grandpa adopted Daddy...
Laura: And when the baby's born, she will have skin like yours: darker than mine and lighter than Daddy's because she's a mix of me and Daddy.
S: I'm adopted, too!
Laura: No, you're not adopted, honey.
S: Oh. (she says with a disappointed look, but then a thought occurs to her) Oh, it's like vegetables.
Laura: How is it like vegetables?
S: When we're at the store and we see vegetables with different colors, they have different parents.
Laura: Yes! Like the tomatoes we were looking at today were purple and red and yellow...
(Yes! We're all just a mixed-up bunch of fruits and veggies, with some nuts thrown in to keep things interesting ; )