In my opinion: Hard match up
Get into her face and don't let her escape. Watch out for DP and jump escapes. Potent for an air grab.
Lack of escape options means if she gets her stein's set up, it becomes a huge game of patience to find holes to work into. Be weary on approach, her DP, anti air's and normals can and will out poke you.
Items:
Cat hammer: For the long poke you need to catch her out throwing steins and other projectile moves. Super it for a better effect.
Frying pan: Use only if you manage a heavy rushdown.
Hammer: Low primers means easy guard break, but that's assuming you get in. Super: She isn't on the ground often enough for it to work but still great in corner.
Bombs: The arc prevents her from jumping and throwing out steins but if she rushes in on the ground, you are open to attack. Same with super but huge radius means better coverage.
Missles: High priority and locks down her game. Super punishes and destroys anything she does.
Bat: Your only way out when she gets you in a corner. Handy to have around but watch out for baits. Same for super.
