Beautiful pose, I especially like how she's placing herself between the trees and following the lines upwards. The little flash of red around her neck serves to draw attention to her face in a very subtle way while still harmonizing with the muted tones of the picture. Nice work.
This is actually my sister and she's not a model or something! Usually, whenever I try to do a conceptual shot with someone close, it ends up with unnatural posing, since I don't know how to direct them myself. So I was pleasantly surprised with the posing here!
*grin* "model" was just the easiest word for me to use for someone in a portrait sort photo, didn't necessarily mean it in a professional sense. Also, I completely understand the discomfort with directing people to pose, I've never really gotten it to work in a natural (though I know it's at least theoretically possible. >.>) Catching people acting naturally always seems to work better. Again, though, nice capture!