To begin, I feel the need to say that your piece of artwork is truly interesting. The concept you have decided upon is agreeably incredible. It is discernible to me that you did the best you could with your faultless magnitude of powers. The shape of this artwork is obviously conforming for the feeling that I feel you are trying to encapsulate, but now that I think about it this comment is probably irrelevant. But, I expect that your implementation of symbolism could of been approached differently as I contemplate that it wasn't able to duplicate the capability seen in the remainder of the art piece. To conclude I would like to say that it has been a pleasure to pen this critique for you and I feel it will enable you to revamp your already masterful piece.
Well, not Martha Stewart, maybe, but the face does look unique - not the usual, cookie-cutter super-heroine face that you usually get, it looks interesting and almost tears your eyes from that little piece of heaven just underneath it. The details on the hair and the costume (belt buckle, rope thingy) are very well done, and the cape - especially the shading - looks great. You gave a lot of respect to the pencil, allowing it to come through and it mostly works - the rather crude line eccenuating the breasts looks a bit out of place. The subtle lighting wors beautifully. Over all, excellent work.
I love this piece. My only complaint is not with the art or coloring, but with the title. Based on her face she looks older so I would have gone with Power Woman myself. A great picture (and IMHO, its long since due that Kara/Karen go from girl to woman).