I always send my DD in with a water bottle to have at break/s to help keep her hydrated. Always comes back full but at least she has it. She's also getting a little snack provided at break by school and shall send her in with the obligatory clear plastic bag with pen/pencil etc. Tissues are a must for us as she gets a bit sniffly though I have always checked this is alright when dropped her off, which it always is. She was under the weather for one of her GS exams and I asked if she could have some unwrapped cough/sore throat sweets during the exam. They were completely fine with that, as it was think she only had two during all exams. I am quite impressed with the fact she can wear her own clothes for her upcoming indie exam. I think it helps everyone feel 'the same' and at ease with one another with no prep/state divide as it were.
Possibly a stupid question, but why do the bottles need to be unlabelled?
Good luck!! Oh my, still yet to do any proper revision here