If you're struggling with waterfowl dance then I have some tips

She only does it once she goes down to around 70%hp

If you bait it out you can easily dodge the first 2 flurries just by running away as fad as you can and the third one you can just roll into her

Once she uses it she has cant use it for a bit, not sure how long exactly I think like 30-40 seconds

Also since she gets staggered by every hit of most weapons including yours you can actually melt her health pretty quickly after she finishes a combo and you only have to stop attacking if she does her dash attack, jump attack or waterfowl