Wow Alison! You really have a great start to your ADR's!
Since you're traveling with two little ones, I am going to suggest one place that does not require Advanced Dining Reservations as well as one requiring reservations. I also have two kids around the same age and I know you sometimes need to be spontaneous with meals.
For a great meal outside of the Theme Parks, I suggest
Beaches and Cream Soda Shop at Disney's Beach Club Resort. It's a whimsical, fun diner atmosphere with amazing food (the onion rings are to die for!) and great milkshakes and ice cream creations. Our little ones love it there! It's a great place to beat the heat and have a some fun while you dine.
If you're on the Disney Dining Plan and need another ADR, I highly suggest dining at
Biergarten in Epcot. It's loud, fun, and the buffet meal offers a fantastic selection of choices sure to please even the pickiest eater. Your kids will love dancing and singing along with the band. You'll be saying "Oi! Oi! Oi!" before you know it!
I hope these suggestions are helpful, Alison! Please let me know if you have any other questions about your magical September vacation. I've been traveling with our toddler and preschooler since they were infants, so I have lots of experience navigating Walt Disney World with little ones!
Pixie Dust,
Ashley