Tara,
You are almost there! Here is where I would go;
- August 22 - Magic Kingdom
- August 23 - Hollywood Studios
- August 24 - Magic Kingdom
- August 25 - Animal Kingdom
- August 26 - Epcot
- August 27 - Magic Kingdom
With younger children, make sure you stick to the schedule of the 4 year old, as all it takes is one tired child to ruin it for everyone.
Make sure you do the rider swap, letting you and the other adult enjoy a few thrill rides that might have been otherwise off the menu.
Consider walking to the Magic Kingdom from Bay Lake Towers, rather than walking to the Contemporary and then monorail over. You will find it is both quicker, and kind of a nice change of pace!
Make sure you see what extra activities are going on in your resort. They are often overlooked, and really fun! They can also be fun to try out when one child needs to be in bed, but the other adult can take the older kids out. They also get happier about not having to turn in early because of a younger sibling.
Finally, you are there at what should be a moderate to lighter crowd time, so feel free to enjoy Extra Magic Hours.
Have a magical vacation!