If people will tolerate one more post on the subject, I want to express what really hit a nerve about this article. When she asks "Is there such a thing as 'the sex of one's brain'?" It calls to mind recent discussions I've had with people I care about when I've told them I'm non-binary.
They are sympathetic and caring, listen to what I have to say. But I can tell that they're not sure whether to believe that a person can be mix-gendered. They understand what I mean, they're just not sure it can happen.
There's no way I can prove that some parts of myself are female and some male. But as genderqueer folk, the "burden of proof" seems placed on us if we want people to accept us as we are.