Well I think is this one of my favorites you've done. I think her pose works good for the comicbook nature. As I'm been studying comic book poses lately having her forearms flexed is really important and I'm getting that here. The detail in her hair seems at just the right level for the minimalistic style you have in the rest of her body. I think her eyes really stand out. I am pulled into her gaze from the dark outlines and eye lashes you have. The small shadow off of her rib line is appropriate for relaying the form of the pose. My only area that I would consider needing revision is that if you are going for the current supergirl her skirt should be blue and have ruffles like a cheerleader skirt would have. I think this skirt might be a bit short and bland.

Over all I love this piece. I can't get over her hair and eyes. Its one of my favorites!