Damara, it does really seem as though female coworkers are so much better at the whole respect thing. When my hiring manager found out, she apparently responded with, 'I hired a female, so they're a girl' (I've yet to find out whether this is true or not), however when I briefly and awkwardly requested she use male pronouns, she was completely okay with it without making a fuss about it, and hasn't even slipped up once since.
Some of the male managers, however, pfftsh. I actually misgendered one manager until he sorted himself out, haha!