Not sure this is what I want to know
well..... my cousin has bigger boobs than her mom so its possible she is a d4.
Honey, they'll get bigger in time trust me!
Think of it this way. Given the choice, would you choose a girl with smaller breasts or a girl with bigger breasts? You would pick the woman with the bigger breasts, wouldn't you? It's the same for women.
I personally think that it is up to how the girls breasts are growing at their age, everyones breasts grow at different ages! I am 11 years old and Im wearing bras. But still girls that are my age have bigger breasts than me. hopethat helped :)
Answer Maybe they are bigger 'cause they are adults. Or people grow differently, sooner or later you'll have big breast.
Because it's a part of growing up. Also it has to do with puberty. To make it simple girls are developing or becoming women.
If you are a boy, look at yours, now imagine that about 10 times bigger.
The make you breasts look bigger but they do not make your breasts grow bigger.
Big breasts, growing waist size, bigger buttox.
Girls may have small breasts but they are still girl breasts.
Puberty is the answer to both your question. And if you want bigger ones after puberty the only option is surgery.