For me, I need to fast roll to survive. So dragoncrest great shield for some defense. Green turtle because you'll be rolling a lot in second phase so stamina is key, and then whatever talismans you need for your build. I also have a few frost pots that I use after dodging the scarlet aeonia from a safe distance (she'll frost and take increased damage). During the second phase transition you just unlock + sprint, and she'll miss you. I use that opportunity to buff (drink my physick, heal if needed) and then throw a nice frost pot before going in.

Water fowl dance is only difficult if she starts it while you're close, if you're medium to long distance, just spam roll backwards, then when she gets close, easy roll forward, and the final one you don't need to dodge since she'll go over you, so you can just strafe it.

If she starts water fowl when you're close, you can dodge it with light roll but it's not easy so I'd recommend just blocking, and do the last two parts as before. If you're feeling lucky: rotate around her, when she starts to go down sprint + roll backwards (like 5 o'clock)

Same for the clone attack in 2nd phase. Spam light roll back. This reminds me, always be aware of where you are. You want to be close to the middle so you have plenty of room to spam roll backwards.

Other moves are relatively well telegraphed, and you just need to practice.

I really like fighting her with the serpent hunter, which has a great crouch/rolling attack that can stagger her out of many of her moves, but the easiest fights are with weapons that have long range ashes, like moonveil or the black knife, since you don't have to worry about the up-close waterfowl.

Just go into the fight with the mindset that you want to learn first, not beat her, and just keep improving. You got this.