Well besides learning when to dodge, here are few tips:
At certain point in a health bar, you'll stun her for a bit. so map them for an extra hit
Hit her once and run
Use T to taunt her when you are in a safe distance so she jumps at you giving you a free hit
when she thrusts, 1 dogde anywhere, 2. dodge backwards so you are close to her to hit her
when she uses long range atk, you dont have to dodge, just move to the side
BTW you dont get any scene for defeating her, this is a BIG shame...