I would add to the PPs list (or as much as suits your family's needs):
1 change of clothing per person
2 sets of underwear per person (don't forget socks!)
1 swimsuit per person
1 set of pj's per person
Your almost empty purse
Medications, eyeglasses, sunglasses, extra contact lenses, etc.
Electronics and chargers (only if they don't have to be inspected separately by TSA--those go in your tote bag!)
Toothbrushes, hairbrushes, combs, razor for DH, etc.
I would do one shared carry-on with those items, plus any other basics you deem essential for 24 hours if your luggage should go astray. It probably won't, but just in case! If your children are small enough, you might be able to bag each child's clothing to make your life easier--or use the compression bags. Edited to add: You want to pack this bag so you don't need to open it going through security. If you need to use two bags, go for it. I'm just trying to minimize the number of bags you'll have to keep track of!
In a small backpack, duffel or totebag (to fit under seat):
Contents of your purse (if you carry a purse rather than backpack)
Tickets, ID, Itinerary (be sure to put a copy in every bag--including checked ones!), confirmations, travelers cheques, credit card, money, etc.
3-1-1 bag for everyone (toothpaste, lotion, sunscreen, shaving cream, antibacterial gel)
Magazine, book, etc.
Camera (easy access) and/or electronics that have to be screened by TSA.
Tissues--little things you may need during the flight.
Some snacks, depending on length of flight.
For each child--who is responsible for his/her belongings--a small wheeled bag or backpack (to fit under seat):
A couple of small favourite toys or items that can't be left at home.
Colouring books, paper, crayons, pencils--whatever will keep them busy during the flight.
You didn't specify ages, but if you have an infant...
You probably already have that covered!
Hope this helps!
