Without knowing how tall you are, it is impossible for any of us to give an educated opinion.
Just take a look at the other women your age who are the same height. If they look overweight, you can judge from that.
Since breasts are made from glandular and fatty tissue, you definitely will need some body fat to develop a good size breast. The food you eat makes a big difference in how much body fat you will develop. Eat lots of vegetables and fresh fruit. Avoid processed foods and sugar of all kinds. Go easy on the meats, eating mostly fish and chicken.
Also, most importantly, do not expect breasts bigger than any of your female relatives with the same weight as you. Genetics and hormones plays a very big role in breast development. ( o ) ( o )