When people ask what body shape I have, I usually go with "Inverted Pear." It's similar to hourglass, but that usually comes with equal bust and hip measurements. I'm a little bigger in bust than I am in my hips, too. Your hips may get bigger on their own, you've got some time left to grow.
Don't worry so much over the numbers, you're well within proportion and at a healthy weight. I've been 5'3" and 104 pounds since I was 15 and the only real complaint I have about my body shape is that it's miserable finding a good bikini around here.