A few years ago I saw a really tall girl aged about 16-17. Even from a distance it was completely obvious that she was just a really tall girl and not a man. Why was she not mistaken for a transsexual - by at least some people? Well, from a distance and close up her gestures and body language were naturally feminine, not stiff, mannered, or overly feminine, like many a nervous, unsure transsexual. Her hair and face contained no hint of masculinity, and as a genetic female she obviously didn't have to worry about her voice.
Tall men almost always will have broad shoulders, big hands and feet, or at least two out of the three. What gave this girl her poise and confidence was her knowledge that had anyone seriously questioned her gender then she would have been able to quickly and easily satisfy any doubters.
Love that dress!