Big pants that will go up above your wound, slippers that you can just slip on so you don't need to bend over, a dressing gown for that walk from your bed to the operating theatre otherwise you're going to be flashing your bum, lol.
You'll need extra baby clothes as the stay can be longer, although I was still only in for 2 nights and had too many baby clothes, OH was forever taking them home on visits, lol.
Loose fitting clothes for you, I highly recommend a nice loose dress, that way you can actually get dressed and not spend the whole time in nightwear!
Bring lots of maternity pads and extra baby wipes, you'll probably use them yourself for general freshening up.
Personally I didn't need this, but a lot of people said a small pillow to hold against their wound when they stood up really helped!
I will edit if I think of anything else, it's been a few weeks and I have baby brain, lol.