You know I'm not expert in pencil drawing (that's what you got Brian for) but let me tell you that you're really improving over your past work; and this is a fine drawing you have here, which really captures the viewer's eye.

Your technique has definitely improved, with a lot more attention to detail and noticeable progress in drawing hair and shading, great job on the eyes and the hair decoration on the left (of her face).

However, you still need to pay more attention to detail and proportions. For example, the necklace is too flat, I think you needed to emphasize the shading more, so it'll stand out more; also, I don't know how was your reference photo, but the necklace looks too small when compared to the rest of the elements in the portrait.

In proportions, I believe you have to work more on how lopsided the face is; personally I believe the left side of her chin is too big, even considering the angle, as well as the shadow outlining of her left chin needs some refining, because part of the shadow cut right into where her face would be.

I'd like to see you take a shot at a different drawing style, so far your realism work have been portraits up close; and I think it'll be worth it to jump into a different style as part of learning more techniques and broadening your vision.