Hi Kaitlynn,
Thanks so much for visiting the Disney Parks Moms Panel with your questions.
Mickey's Not-So-Scary Halloween Party is such a fun event. I have attended with my family, and we had a great time!
Because Mickey's Not-So-Scary Halloween Party is a separately ticketed event, those without a ticket will need to leave Magic Kingdom Park on the evenings of the party. If you are at Magic Kingdom Park on a day with a party and do not have a ticket for the party, you will need to leave Magic Kingdom Park by 7:00 p.m. For this reason, many people who are not attending the party choose to check the
Walt Disney World theme park hours and pick days to go to Magic Kingdom Park when there is not a party scheduled in the evening, to allow for a longer time in the park.
I think that attending Mickey's Not-So-Scary Halloween Party with your 5-year-old daughter is a wonderful idea! My first suggestion for you is to dress in costume. Everyone in your party can dress up! If you can theme your outfits together, all the better. The year that we went, my daughter dressed up as Tinker Bell, so my husband and I dressed up as fairies as well! We got some great compliments walking through Magic Kingdom Parks with our wings on. I also suggest that you prioritize doing things that you cannot normally do during typical park hours, such as trick-or-treating around the park, and taking in some of the special entertainment. I especially suggest Mickey's "Boo-to-You" Halloween Parade and the amazing Happy HalloWishes fireworks.
I hope that these thoughts are helpful for you, Kaitlynn! Have a great time planning your vacation, and please do not hesitate to ask if you have any further questions.