Oh hun, ni know you've been worrying about it... massive

It can't hurt to have a spare change of clothes or an over night bag packed JIC, when Z had her nose fixed i took her in in some comfy PJ's and a dressing gown and had other clothes packed. I let her take her baby and i made sure i had some things on the iPhone to keep her occupied while we waited.
Dr's suggested alternating panadol & nurofen for the first 24hrs just to help with her comfort levels so it might be a good idea to have a back-up supply.
A portable DVD player can be a good idea for afterwards so she can just lay back & relax but sometimes they will have those in the day surgery area anyway... can you call the hospital and ask for any suggestions and see if thats an option as sometimes it's easier NOT taking a lot of things IYKWIM.
The RCH had little coloring packs & things for the kids while waiting aswell which Z loved.

Miss E is a very strong little girl and it will break your heart to see her go off to surgery and come back again (as it does for every mum) and it's ok to be nervous, hell i wanted to vomit the whole time we were in the waiting room, you know i am here and you can text me a million times that day if you need me.
Sometimes knowing the ins & outs can make you feel worse so get the information you NEED and then just go with the flow on the rest, but just letitng her pick things that make her comfortable will help you guys a lot more too.. she's a clever girl and she's a strong girl (just like her mum) and she will come out of this prefectly surrounded by love and comfort