Like I said in the other thread, she can do what she pleases as long as she isn't hurting anyone. It's her way of expression and experimentation. Go for it.
But it's not okay for a guy to wear a dress? Since a lot of guys don't wear dresses?
And as for the title change, if she can, go for it. For a woman to grow a beard, a legit beard, that's kind of tough unless they have a hormone imbalance like hirsutism.
A guy that wears a dress is somehow expressing himself. I can't see how growing a beard could be a form of expression for a girl. What would she want to express through it? Most (if not all) girls I know can't even grow proper facial hair.