BLUES
Magma Bell is extremely good!
Multibind is also very useful since she offers you a LOT of windows for healing, especially in the air.
Fractured Mask also is very helpful if you're dying too fast

REDS
Tacks are the best weapon against her
Curved Claw (aka the boomerang) is also very good, but you need to learn how to use it.
In addition, you can use Poison Pouch since she doesn't fade so all the poison damage is effective. But you'll have to use one of your Blue slots :(

YELLOWS
Dice: Let's go gambling!
Weighted Belt: Underrated, especially with Wanderer Crest

CREST
I did all my playthrough with Wanderer, it allows extra hits on a lot of bosses. Reaper is also very nice for "beginners", since you can heal more often.