I have a 7 and 4 yr old and continue to bring the same items w/ me~
stroller fan plus batteries , at least two of these they don't require batteries just some water and we usually stick a few cubes of ice in when the water isn't cold enough I bought them at walgreens for 7.99
https://www.mistymate.com/shop/comp...d,0/option,com_virtuemart/Itemid,26/vmcchk,1/, hat, sunglasses this is a must have for my dd7 and for dd4 we use the ones that strap on you can get them from target for about 5 dollars, sunscreen, solarcaine just in case this is good for everyone, I bring a tide stick w/ me it came in very handy when my MIL add one of the lipton drink packets to here water and didn't close the top and she sprayed me all over my white shirt w/ tea maybe even some shout wipes, a tube of benedryl cream for bug bites, tylenol or motrin.
Most of these items I don't carry w/ me I have a couple of the disney backpacks from the
disney store that we bring and I use one that I back the diapers and wipes and a travel mat changer my dd4 is disable and still in diapers and eats baby food so I carry these in the main part of the bag in the two front parts I put my camera (I have a small digital), maps and what nots that I need easy access to. I remember w/ my older dd and mostly b/c she is still like this when we are in disney she doesn't really want to eat but the main thing I am able to get her to eat is the fresh fruit so I know where all of the fruit stands/carts are, we bring the drink packets koolaid, tea, crystal light b/c we don't really care to drink all of the soda while in the parks and when we need something a little more than water they work out great.
sorry this is so long I could go on but I will stop so others can add some if you have any questions feel free to post or send me a pm.