My babies went camping for the first time as infants ... but we took a Coleman pop up rather than do our usual primitive camping.
I've never known of anyway to make a hot tent cooler if there is no electricity or breezes blowing ... I would love to hear some of those tricks ... the only thing I know to make a hot tent cooler is to camp in spring and fall rather than the heat of the summer, or to camp in the mountains near the river .... that'll get ya' pulling for the covers at night!!! If there are primitive sites on the river, get there as early as possible because they will get snatched up first and fast ... a day ahead of the rush is best!!
You're smart to take things to entertain your babies ... just being outdoors helps, but they are still babies and need to be distracted from boredom when it strikes!!
Plan for crawdad digs, digging for worms, fishing, searching for the perfect rocks and driftwood .. take some paints to decorate!! my now grown girls still have favorite rocks they picked up on our annual camping trips ... take a tree/plant book with you from the library and help your oldest identify some of the areas native plants!! Take some paper, glue/tape, scissors,crayons and yarn. Prepunch holes in paper for book styles. Then collect things from your nature walk for her to glue into her book ... don't try to do it all in one sitting ... just pull out a page to do at a time ... find out what kind of leaf you have, glue it to the page, label it with crayons!! page one done!!! Take a good family photo while you are there and add it to the cover when you get home with the title "The Herb Family Camping Trip ... Turkey Run 2011" .. or whatever suits your fancy.
All of her distractions can be packed in one backpack just for her!! Including a favorite sleep toy, pillow or blankie!! Just make sure it's not to heavy for her to carry.
Take her bike if possible ... jump rope, small shovel and bucket, battery powered radio or her favorite cd for quiet time. For the most part, my girls had cousins to play with ...
Oh yeah ... Watch out for the raccoons!!! Lock your food in your vehicle at night. Aluminum foil, tupperware lids, trash bags hung out away from the tree, trash cans with lids ... none of these will stop our nocturnal friends ... don't lose your food the first night .. trust me ... lock it up!!!
Oh, and if you do catch some crawdads for tomorrow's fishing trip, don't leave them swimming in a bowl in the creek for tomorrow's fishing trip!!!!! see note on Raccoons!!!!

I'm just sayin' .. been there, done that ... had to listen to the girls cry for an hour and still hear them lament about all their hard work become raccoon food!!
Have a fun and safe trip ...