Most of the detail in the pic is quite a breath taker, but it's more of body positioning and and the inner details because most people would over look the colors and such.
While it is a good pic, there are a few problem present, one being her position on this rock at sea is not well focus since this image has a focal prospect as to looking up at the character in an angle and how she was draw for this view is not well applied, it should be exaggerated a bit, but not by too much. Next I wanna get at that right leg, actually both thighs on both legs really come too short, they need a little more length for it's detail. Another thing to note, this character is in position as to where she's lean a little far back on that rock but this is where most of the issues are. There is no support from any limb on her body to balance on it, if your going to use that left hand is what is helping her as the ticket it won't work since this hand isn't even supporting itself against even the rock for that matter, and the breast are draw as that if the character would be as a more standing 3/4 type of view.
People may think your a great artist, but you still need some work, practice never hurt a soul.
While you definitely a lot of detail on the character, and you used color skilfully as well, it appears that you did not put the same amount of detail on the rocks and the formations in the background. The rocks look like simple two-dimensional polygons rather than actual rocks, and the rocks don't have the same level of shading as the character. Also, the character is placed in an awkward position, leaning a bit too far on the rocks. This position looks too uncomfortable for reading, as she would have to lift her upper back up just to read her book. If you had the character sit directly on the rocks, instead of leaning on the rocks, her pose would look far less awkward. Finally, the character does not appear to have defined hips. The legs look like they're just jutting out of the torso instead of naturally progressing from the torso. If those three things were improved, the picture would be greatly enhanced.