No you dont get to choose her gender. Its not your life to live. She gets to choose her gender. She doesnt get to choose your gender either. The door swings both ways.he is a man. I do get to choose the sex because thats how he was born..
She was born a biological man. We get that. Thats a statement of objective fact. However she chooses to identify as a woman. You dont get the right to take that choice away from her, trivialse that choice or belittle her on that choice.
This isnt a question of debate. Dont do it. Its ignorant at best, and a form of discrimination at worst.