The shading on this is very well done and smooth. It's hard to shade with one color like that, but you managed to do it perfectly.
The sepia tones gave a nice feeling to the picture, seeing the character comes from a desert.
I can't see any anatomy mistakes, and you drew her torso beautifully.

The flow of the hair is wonderful, and I like the shading on the jewelry. One tip: when shading gem stones, the highlights should be placed on the direction opposite to where the light hits it. A good tutorial for that can be found here [link] .

And to finish up, nice pose, I've never seen someone draw Nabooru like that.

Overall, I think this is really great. The sepia tones used make a really great effect, it suits Naboroo's character/story a lot. If this is the style you're following with in the future, then I'm super excited to see all the new work you'll come out with!
This picture really shows a great understanding of anatomy, I really like her foot showing underneath her sword, and her abs look really great. The shading is noticeable, but subtle enough that it doesn't look like her ribcage is going to poke out of her. I like her pose, it's unusual and obviously not something someone would do naturally, but I think that's totally okay. It engages your eye and keeps you interested. There's a great silhouette going on, so even if everything was darkened in you could get the curvy shape.
The detail on her clothing and everything is great, and I love how it's shaded. However, I think it could be improved just a bit on the hair. Closer to the hairpiece on top, the hair is darker. If that kind of shading was used in other places too, like the long strand that stretches to her arm, and the large mass of hair near her body, it would look shinier and add a little more depth. I can already see that it's there, but it could probably be darker.
Also, I think it would've been a little more 'airy' looking if her head was tilted back just a little little bit. Obviously it's too late to change now (don't want to erase that beautiful face just to tilt it a bit!) but it might be interesting to experiment with in the future, instead of just having the face full on.