You should do whatever you want with your body. I don't know, given all the breast enancement surgery going on it seems that most girls/women who have small breasts do not like them and would prefer to change them. Not only that, I think the perception (as well as the reality, for that matter) of what is a small breast, what is a large breast, etc has been changing pretty drastically. But you personally are under no obligation to rebel against the tide, you should take whatever advantages you desire.

Anyway, enough about breasts. On a practical note, if we're talking feminine/ attractive appearance, the thing that really makes a woman obviously look a woman is the hips, especially the waist to hip ratio. Is there anything you can do to achieve that? If plastic surgery is an option that's on the table, can you inject fat in your hips, butt, and thighs? (I'm totally serious) Or do hormones help enough in this regard that it's not necessary?