I don't think you would loose anything here by staying with color. In fact, the skin tones might be enough to push this up from the 8 that I rated it. Very nice.
Good use of black and white and light. Just 2 things, some kind of weird shine on her nose (at least on my monitor) and I wish you hadn't cut her pinky off :)
This image almost hits the "mark". I think it is printed to dark as I can not see detail in the hair. I and can not tell what she is holding. I think you have the makings of a good image here but you need to do a little more work.