Yeah I'm pretty sure that this person is transitioning from a woman to a man (which I know is not the most accurate way to put it, but I don't want to make a massive text-dump about this issue here) and retains female pronouns on Facebook so that people don't give them shit about it.
Given that this is Tumblr, they could be lying about that too, but I'm going to assume they aren't until proven otherwise. This cosplay story, on the other hand, is a mite fishy.