ANDY'S ANSWER: Well, this is just a guess, but I would say you still have a couple more years to grow. On average a girl continues to develop until they are in their late teens. Also, the fact that your mother is big breasted would indicate that you probably have not finished developing yet.
Regardless of what size your breasts turn out to be, they will be perfect for your body. Learning to love the body you have is a big part of maturity. Try not to judge your own beauty by what you perceive to be other people's standards. Breasts are a pretty small and unimportant part of the whole package, no matter how big they are.
Below is the recording of Andy answering this question.