at this point, I'm assuming she was always a gal. In my mind, she preferred wearing male clothing and hair style over female stuff.
and then after reincarnating, realized that wouldn't fit the villainess style.
disclaimer 1: I have been banned previously by guessing at future content without using spoiler tags.
disclaimer 2: This isn't a spoiler. This is based on previous chapters.
disclaimer 3: This isn't a spoiler mainly because this is just an assumption based on nothing but imagination.