Don't forget everything the others said, plus:
a couple of spring clothespins for closing the curtains tight at night and for closing the unfinished bags of chips, etc.
nightlights - at least 1, maybe 2. We bought the cheapy ones at
Walmart so it wouldn't matter if we let them.
a flashlight - just in case the power goes out. There was a storm the first night we were there, and having a flashlight was a relief.
baggies of all sizes - trust me!
bandaids. altho they offer first aid at every park, it's always waaaayyy out of the way when you need it.
wet wipes - even if it's just grown ups going.
extra batteries for the camera
water bottles - they are $2.50 at the parks this year.
Have a great time! We did!!