I really love how you shaded Sharon - the brush strokes are very nice looking and I like how detailed it is in places (especially the face and left arm). I especially love how the texture makes it look like an actual paintbrush was used so the shading has a rough look to it, but not too rough. The way you did the trees is really nice, too - it definitely shows off the uneven surfaces and gives off a lot of detail.
Another thing I love here is your distribution of colors and making sure one color doesn't overpower the others, and not just in the foreground, but I even noticed the specks representing flowers in the background, too. It's all brightly colored and really helps the forest stand out. Speaking of colors and the forest, I also especially love how you did the grass - it obviously took a lot of work to do all of those blades and it shows. Not only that, but the trees in the back are done wonderfully and I love the fog effect you used for the ones that are really far back - that and the colors you chose for the back actually make me think of a nice, warm, welcoming morning vibe. I don't know if that's what you intended, but it goes wonderfully with the general theme of the pic. Also, while I personally think you could've stood to add a few sections of leaves along the very top of the picture (mostly to give those trees in the back a little something extra to work with), it would've only been a minor improvement and the forest stands fine on its own without them.
Given that you've never drawn a pose like this before, I'll cut you some slack on most of the anatomy issues (really, I doubt I could do any better with my abilities), but there are some key areas that I feel you should focus on for future reference: The area that sticks out the most would be her feet in that they're far smaller than they really should be, even with this kind of pose. In fact, I'd say it's not so much an anatomy issue as it is a perspective/distance issue; I know you have problems with perspective and I know I gave you some advice regarding that a few months ago, though I feel you may have taken it too much to heart here. Getting it right is difficult, I know, but I have faith that you'll get it right in due time. On the topic of body parts that are smaller than they really should be, Sharon's left hand looks awfully small compared to her right. I feel the hand altogether should be a bit larger and the fingers a little longer. Only a little, though. Those are the only character flaws that I feel could've been done better.
Another thing I would like mention is that while I very much enjoy your shading and your brush strokes, I really think you should look into textures more. While it's obvious you put a lot of detail into this (such as the bark on the trees), I also feel as if everything looks rather smooth here even when it isn't supposed to be (again, the bark on the trees come to mind, though Sharon's clothes and the rope around her waist are also worth mentioning). Obviously, tree bark is pretty hard to emulate, though cloth, hair, and...er, whatever rope is made of... don't take too much effort to mimic. I usually try to use things like smudging, filters, or both - it depends on what I'm trying to apply texture and detail to - but you might find an easier/more comfortable method. Start with small stuff like that and work your way up.
The last criticism I have lies in the background shading. Compared to Sharon, there doesn't really seem to much of it, and most of what I can see doesn't quite seem consistent with the shading on Sharon - the trees, for example, should be significantly darker on one side and/or lighter on the other, if the shading on Sharon is any indication. The effect is particularly jarring with the flowers on the vines. Yes, the colorful effects are nice, but the lack of shading on the flowers (and on the vine itself where the flowers are meant to be blooming from) makes it feel as if they were tacked-on; a last minute addition, if you will. That's a real shame, considering the vine itself actually does have really nice shading otherwise. Just remember that for future reference, everything has a shadow of some sort, and don't forget about your light source(s).
I know all of this criticism might come off as a little harsh and make me sound like an ingrate, but I really do like the picture overall and I still believe I was right to give you my money. I like your work and I feel you've come a long way since the days when I was still on Yoshi Lore - I want see you improve even further. I have faith in your abilities, and that's why I'm writing this critique - after all, if I didn't have faith in you, I never would've commissioned you in the first place, and by extension I wouldn't even be writing this critique (after all, there's no point in telling all of this to a lost cause who cannot, or will not, improve). I only hope you would do the same for me if the situation arose.