Oh, I was a bit confused by the title. I thought you were referring to a female version of the Tankmen. Then again, I guess there wasn't a tankboy to begin with. It's great to see how your first art submission worked out. I, for one, was quite impressed by this. I'm not that familiar with the character.
It does seem like you captured her essence pretty well. I just now notice the actual tankman down there! I really should look at everything here. Sketches this good deserve to be submitted. You may not be that prolific, but you've made good stuff.