I have? rbigger breasts than other girls my age. this is normal right?

Everyone different: There is not a "normal" breast size. Size depends on your body size, genetics/family and types of foods you eat (foods with hormones). The important thing is to make sure you are wearing the right bra size for your comfort and support. Get fitted by a bra specialist, especially if you are larger than a d-cup ( fyi cups sized go up to m-cup!).