You are the perfect weight for your height . Perhaps you just need to tone up and gain some muscle by doing some light weights. Go to a ymca if you can. They will set up a program for you. You are definitely NOT overweight..
That's an ideal weight for your height, hun. But if you don't feel like that's enough, you can tone up a bit and focus on the areas that you don't like. Personaly, i do capoeira and it works JUST PERFECT to build slim sexy muscles and enhance your metabolism.
Wish you best of luck! :)
Try yoga. It's great for toning muscles.... makes you feel "long and lean".