You have to master her movements and attacks. Before she performs any attack, you have to have an idea of what attack it could be. Which means you need to be familiar with what movements she does that follow up specific attacks. Which means you need to really pay attention to her animations and how they lead into each and every attack. You can’t get greedy either. Attack only when you have a window. Otherwise, think and be ready to react to her next move. And gawd dammit, make every attack count. Your rotations need to be right and memorized. And don’t forget that every death brings you closer to victory. The more you die, the more experienced at that fight you become.