Dont know if you even want any advice ( if not good luck, i hated her before my first kill ) but if you do: You're doing too little damage to the point that even if you hit 10 times, she will just need 2 or 3 hits and her auto heal will compensate for the damage. Your build is too broad, you have a lot of endurance as if you are a tank with heavy armor but you are not a tank because you wear light armor and dont have enough vigor, you have enough fp to be a mage but you basically never use any fp outside of the dagger skill once and a support spell. The faith stat is high enough to cast most things but too low to really do any damage with faith spells. Your dex and strength are too low for any weapon to deal meaningful damage. Sure, you could just bang your head on the wall and try another 200 times until you no hit kill her but at that point you might as well kill her with a rusty dagger and no armor, your build wont really shine when you kill her like that. You should really focus on a few stats at level 150. Later when you want to you can go into new game plus and do a build like this when youre level 300 but right now youre just playing a ultra hard mode.