Actually, the author was asked whether Hange is male or female and he didn't answer clearly. However I believe Hange had on a skirt once so very probably it's a she. The translator must have made a mistake.
In the Snk world, wearing a skirt doesn't necessarily mean you're female. If you notice, the soldier uniform is technically a skirt with white leggings, boots, a random top and a jacket.
I read somewhere that the author meant to make Hanji a girl in the beginning, but his assistants said the way he drew Hanji made her look too masculine. He then found it a pain to explain to the mass, and ended up saying that it's up to the reader's choice what Hanji's gender is.
Hmm...Interesting. I don't agree with the skirt doesn't mean female thing though, because I think Historia and even Mikasa wears femine kind of clothes with skirt when they are not in their uniform but I haven't seen the boys wear that.
What I read once was that the author found it amusing that the reader found Hange's gender confusing and decided to leave it a mystery.
Throughout the whole manga and anime, I thought that Hange is a female! She is actually a He!