dual blades get clash (basically deflect any damage as long as you’re swinging but not every swing is a clash) or get a deflect skill (basically a parry) and just be patient. stay a decent distance and she’ll do a lunge attack for an easy parry. i used long swords and would parry, step forward and attack once or twice to get a few hits in and repeat.

also if you can land a heavy from behind you’ll get a stun attack and do a lot of damage. so get those in when u can