Education:My breast does not have proper size.what shoul i do?

%26lt;actually this is 4 my friend%26gt;she is my same class age 18,but she does not hav enough breast size ,she is slim and beautiful, v both are in the same room in hostel, so we use to do some les in nights,i always noticed that she wear a medium size sports bra,and she and me 2 use to press her breast just for fantecies but there is no increase in size,in my case i notice that while pressing my breast will more offen jump around frm my bra ,what is the problem for her