Because I am completely crazy, I have actually looked up children's clothing, and based The Mooren kids' Fancy Outfits! for their Fancy Dinner! with the Bosko siblings. For anyone who is interested, and for my own future amusement, I am posting the links here.
First,
Alida
Dress:
Tights:
Shoes:
Barrettes:
And the all-important sunglasses:
Theo
Shirt:
Pants:
Blazer:
Shoes:
And the piece de resistance, the hat:
Man. I wish actually had full pictures of what's in my head, you guys. Cutest kids ever.