There is something weird about this fight, I was getting hit by something I couldn't see. It seems that you sometimes have to get away from her.

I leveled up, improved my gear and my build and then I won that fight easily. So maybe you need to gear up before trying to kill her.

Same here....
Nothing to be seen anywhere near my character, and just dropping insta dead...

Same for me - I die because of invisible spells !

Dear devs - have you tested your own game ?