I really love how you did the shading on this work; very classic and brings an elegant look. I love how you did the shiny effects on her top and on her earring. Also, I really like how you apply some details on her especially on her hair.
You did a very wonderful job on your work, keep it up.
I love it! ... But if I could just make one tiny suggestion ... I would add a hint of violet to her eyes. I would totally leave the rest in gray scale but I just think that would really make it "pop," especially since that was one of her most striking features.