I know what you meant, I've just never seen people discuss measurements "across" before (it's usually circumference) so I didn't have those numbers to hand. Still, it looks like you're well in proportion...
I went and re-measured, and even got my wife to cooperate. I am 16" shoulders, 14" directly across rib cage right below the breasts, waist 15", hips 20".
My wife is 22" shoulders, 13" across rib cage, waist 18", hips 24".
Oh, and she's 5'5", I'm 5'7". Basically, that's one datapoint suggesting you're smaller than at least one person who went through a natural female puberty.