First of all we need to be sure that she is really a woman. This assurance does not come from her recent appearance which looks like a woman but must come
through medical confirmed results that the DNA belongs to a female
human being. When a person is a female by genetic structure but
because of abnormality she looked like a male and then she went
through a surgery to remove the abnormal organs and develop the female
organs, in this case she is a female and marriage between a Muslim man
and a Muslim woman is possible. But if she does not have female DNA
and the operation was just for removing the male organs and creating or implanting
female organs instead, she is in fact not a female, so there is no
question of marriage between a Muslim man and such a person.
Same situation applies on a woman who undergoes a surgery to look like a man wth out a DNA confirmation about the real gender.