Can I be honest with you all for a second?
I fart. Yes, I am a woman and I fart. Because everyone farts, it's perfectly natural, and it shouldn't have some sort of stigma attached to it, regardless of gender.
Yes, there are times and places where it may not be polite — maybe try to avoid it in a crowded elevator — but I try to think of it like burping. If it's a place you'd be comfortable burping, then it's fine to let the gas out the other way too.