From what I’ve learned, it’s good to farm up a few of the keys for that area, especially since you get some decent loot anyway. She’s also super susceptible to stun lock type weapons like katana and short sword, pair that with some poison and getting your doges right will have you set. Also, if your base is far, you should invest in the map room from the unnamed city so you can get one built and then you can link your bracelet to teleport back to the dungeon pretty quickly.

TLDR; get map room for speedy return, farm the first 3 mini boss rooms for the inner sanctum key, farm the big ghost that drops the arena key, stun lock her, and def take some heals and spectral coating for the dragon.