Yes ma'am, maybe? Guess it depends on the main language/dialect though. I'm thinking pretty much anyone would respond with respect, maybe be a little fearful of her, she seems righteous but determined. Not one to stray away from the task at hand.
For not working much with humans this looks really good!
onyx
I believe both "Yes, sir." and "Yes, ma'am" are used in the military when addressing your superior.
I think you nailed the appearance though. I'd suggest to remove the earrings though, since I'd imagine there would be a strict dress code in the military. That's just my suggestion though, ultimately it's your call for that.
My favorite part is the eyes. Well done.
GameBalance
Thanks, I guess I will use "Yes, ma'am". I have exactly the same doubt about earrings! I used it to increase fanciness, appeal. As the drawing is a bit simplistic compare to great artists.