Wow. I see why you got offended. When I read the title of your thread, I was assuming you had come to therapy dressed provocatively or something. That might have warranted the "look presentable next time". But a stain? Okay, so a therapist does need to help you become aware of how you present yourself to the world in any and every way and change it for the better (IF you want to). The therapeutic relationship is a good starting point. That's no reason not to be tactful about it, though.
Besides, maybe I'm just very picky, but I certainly wouldn't take seriously a T calling herself a girl, as if she were 15 or something.