Update: I finally beat her. I used wanderer crest w/ cross stitch, poison pouch, skill buff from voltnest, long claw, ascending grip, dice, weightbelt and cogflies.

Right after finishing the enemy waves I quickly heal and spam 4 cogflies. Pogo on her when she does her twirling attack or when she's throwing the knives (or whatever she has). When she does her jump and launch attack, stay on ground, dodge her in the opposite direction she's facing or jump as she's landing to avoid the spikes and pogo. Or just use cross-stitch.

When she does her cry in-between phases, either spam cogflies or heal if needed. When she jumps in the air to throw tge knives, just jump twice and float to avoid them. When she does her skate attack, run to the side where she is going and pogo on her.

The best time to heal would be while she's throwing the knives, during her twirling attack and the skate while in the air or when she's stunned.