I love this topic for some reason. The OP makes me laugh really hard and not at him, but with him.
You ever notice how in general really cute girls/teens always have someone really fat and or ugly flanking them at all times? Their "BFF" or in this case sister.
I had a younger cousin, absolutely beautiful, curly blonde hair, pretty face, blue eyes..then a few years later her parents have a second kid who looks like a beached whale lol.
Its gotta be some kind of evolutionary adaption.