I am a 17 year old dancer and am struggling to lose a few kgs. I eat very healthily and train for two or more hours a day. I currently weigh 50kg but want to be at 47kg, I am 5foot 5.
Please can someone help me.

Assuming that you are female, you may find that despite a lean and healthy diet, and all that exercise, you still have some concentrations of fat around areas of the body you don't want, such as hips and thighs. This may be because of estrogen each of us has in different amounts. I know dancers like to be thin, but you don't want to lose bone and muscle mass either, especially at 17. If you really have cut out all sugars, fats (you need some good oil each day, like virgin olive), and carbs like white flour (you really don't need any flour at all, when brown rice and a few beans provide needed carbs along with nutrients), then cut back just a tiny bit and increase your exercise to include running or swimming.