You are just petite. Just make sure you exercise enough (but not too much), so you can develop a nice body, and not look too skinny. My advice would be to do some weight training mostly. Wear high heels ALWAYS and pants that make you look taller, don't wear bell-bottoms or capris and don't wear clunky shoes or ones with straps around the ankles, they will make your legs look even shorter. Wear your hair at shoulder legnth and NOT longer, this also makes you look shorter. Most importantly: Don't pay attention to people who say rude things they are probably jealous(and fat), make the best out of the body you have, I bet if your spirit is kept positive, you will look even better!

You're small :) I was that height and weighed that much when I was in 7th grade before puberty. Being petite is pretty good because it's cute, IMO ^-^