Great capture with the perfect pose but it looks very flat, I looked at the histogram and the right plus left channels can be adjusted.

If you use PS go to image/adjust/levels.. A pallet with a histogram will come up, you'll see 3 triangles, While holding the alt key on your keyboard click on the left slider and move it to the edge of the histogram, this is your contrast. Do the same for the highlights, the right slider. Don't worry about the mid tones, they look after themself..

I adjusted your image and it looked loads better...

Nice work.
Tony