I agree with Sir. Really, none of the Trans women I've met WANTED to be a girl, they were BORN a girl, but with male genitalia. They just WANT their bodies to match.
But, it all depends on what gender they are attracted to and how they view attraction. If they are attracted to women, they're gay, men, straight, both bi, no preferences pan. Any variation that any person born with the correct anatomy can have. It isn't limited to how you are born.