Having camped in what seemed to be the wettest week in history, where we broke our tin opener, the tent leaked and the water supply to the campsite was intermittent, here is what I would also suggest ;
Plenty of carrier bags, make sure they don't have any holes in them and they can be used for - hat or cape in case of wet weather, a lining between dry socks and leaky boots, something to sit on if the ground is wet, emergency wash bowl, emergency water carrier,emergency pillow, emergency poo bag (!), storing wet/dirty clothes and to keep a dry, clean set of clothes in (which you then keep in the car until your last day so you have something clean and dry to travel home in :)
Enough socks, if your feet are warm and dry, it makes a world of difference.
Fresh scented bodywash/shower gel with matching soap and talc/deoderant etc, so that even if you can only do a pits and bits wash, you smell clean (especially if you are in a small tent. Use one of the breath freshening toothpastes too.
Small storage box with lid (the type that fit inside each other) when empty, everyone to bring no more than will fit inside it. Clothes inside will keep dry (especially when kept inside one of your gazillion plastic bags) even if the tent leaks, the boxes should keep the living space tidy without the need to nag :) and can be used as a seat or a shelf to keep your torch etc handy.
Simple First aid kit.
Needle and cotton and safety pins.
Boxes/container to keep your food tidy/dry.
More than one tin opener!
Lots of loo roll :)
Paper & pencils and a small nature book as you are bound to see an animal/bird/plant that you don't recognize.
Two packs of cards and a bag of pennies - it's not a camping trip if we haven't played Newmarket!
Have a great time, we have loads of happy memories of our camping escapades and are looking forward to creating more :)