I have beaten her soon after leaving my reply of “I’ll just buy a ton of stamina drinks”.
I was only like level 6 strength and I don’t remember my what my body was, probably the same. I think I also lucked out with how she attacked, because she often just did the thing where she keeps a stance, so I was able to refill stamina.
What’s weird is that I kept dying when wearing civil clothes, but then when I tried to wear the maid outfit, I got lucky with her attacks. I was also using the dull knife as a weapon.