From the chat logs that Manning had with an FBI source:
Wired July 13, 2011 by Evan Hansen
Manning-Lamo Chat Logs Revealed
(10:19:53 AM) email@example.com: You mentioned gender identity, I believe.
(10:19:59 AM) bradass87: ive had an unusual, and very stressful experience over the last decade or so
(10:20:53 AM) bradass87: yes… questioned my gender for several years… sexual orientation was easy to figure out… but i started to come to terms with it during the first few months of my deployment
(10:21:09 AM) firstname.lastname@example.org: May I ask the particulars?
(10:21:34 AM) email@example.com: I’m bi myself, and my ex is MTF.
(10:21:34 AM) bradass87: im fairly open… but careful, so yes..
(10:22:00 AM) bradass87: im aware of your bi part
(10:22:24 AM) bradass87: uhm, trying to keep a low profile for now though, just a warningOf course you can't change your gender, only words have gender, men and animals have sex, but you can mutilate yourself, but according to your genes you are still whatever sex you were born with. That can't change.
But given precedent, while Manning is in prison for the rest of his life, the taxpayer will be paying for for it.