Amanda,
OK, so scheduling out your days does help a lot. But you are coming at a lighter crowd time, so I would just focus on the what park/what day plan, and since there is a free dining promotion at the same time, also plan your dining.
So for the park days, I would go with this;
- September 17 - Magic Kingdom
- September 18 - Hollywood Studios
- September 19 - Magic Kingdom
- September 20 - Animal Kingdom
- September 21 - Epcot
- September 22 - Magic Kingdom
I think your daughter will have more of interest to do in the Magic Kingdom, thus more days there than anywhere else. Within this daily plan, I would get a guidebook and check off the attractions you want to do in each park, as well as mark those you want to avoid. Then just approach the park with a bit of a plan, but not too much. Head to the land that most appeals to you, but don't over think it.
It is, after all, a vacation!
With the lighter crowds you will find that you don't have to run around like crazy just to get to all the rides of interest. So relax and enjoy yourself!
If you need help with dining suggestions, just let me know!
Have a magical vacation!