Is 34B a big bra size for a fifteen year old that weights 115?

Everybody has their own shape and size, and is built differently, so size like that really doesn't matter. But if you look at all the girls in the world, age fifteen or so, i would say that that is pretty normal. I am 16 and have CC, but my family has larger bones so my shape is a little bit bigger. It's okay that you have 34B. Everybody has their own different shape and size.

I think that is too small my cousin is 9, and is a size 34b, and I am 11 and a size 34b

34B is fine for that size. I'm 115 pounds and 15 years old too but I've been trying for 2 years to get a good bra that actually fits.