Should be, probably. But Buddhism is a little complicated that way. There are nuns, but they're a little different and they live separately to the monks in the temples.

[And then there's the way temple politics are structured in Saiyuki-verse which??? God, don't make me go too into it. Also yay headcanon ahead.]

But my position is unique. I'm not the first female Sanzo, but it isn't common for a woman to be appointed one either.