Welcome to the Disney Parks Moms Panel Taika!
Your question was cut off but I'm assuming you're asking if you should plan for 2 days in the Magic Kingdom (MK). My recommendation for that age would absolutely be to spend 2 days in MK. While all of the theme parks at Disney World have something to offer every age, I personally think MK has more rides, shows and entertainment for the young and the young at heart.
I'm not sure which other park you plan to visit on the other day but I looked at the online calendar for MK during your visit.
Mickey's Not-So-Scary Halloween Party is being held on Sept. 20th. The park will be closing at 7 p.m. and only Guests with a special event ticket will be allowed to remain in the park or enter the park after that time. Keep that in mind when you're doing your planning.
You may want to look into booking a character meal for your daughter at MK. The Crystal Palace and Cinderella's Royal Table are both excellent choices. She may also love the
Bibbidi Bobbidi Boutique.
Here are some
tips for traveling with younger children that I assisted another Guest with that you may also find helpful. I wish I had some good news about the weather but its typically still pretty warm in September but I can offer you a few
suggestions to help beat the heat.
Wishing you minnie magical memories :-) Allison V.