Hi Anna,
October is a beautiful time to visit Walt Disney World. My daughter is now eight years old, and we have often visited in October with her.
A great special event in October at Magic Kingdom is
Mickey's Not-So-Scary Halloween Party. On select nights, you can enjoy this fun party which includes entertainment unique to the party as well as the opportunity to trick-or-treat throughout the Magic Kingdom. You do need to buy a separate ticket for this event. As to the other Disney theme parks and which you should visit, it will really depend on your unique family. There are great attractions for 7-year-olds at all of the theme parks! My family loves a trip to Epcot, in fact, my daughter would tell you that it is her favorite park. We enjoy many of the attractions together, such as Soarin' and Spaceship Earth. During your visit, it will be time for the
Epcot International Food & Wine Festival. This is a great way for you and your children to sample food from around the world. There are great shows and attractions for children at Disney's Hollywood Studios, including Toy Story Midway Mania! and Fantasmic!. If your children are animal lovers, spending more time at Disney's Animal Kingdom will probably be fun for them, including a ride to see animals on Kilimanjaro Safaris.
I suggest that you order the
free Walt Disney World Vacation Planning DVD. If you watch this with your family, you can all start to decide which theme parks and attractions are the most appealing to you. I would love to help you plan more Anna; however, I am limited in the space that I have to answer. Please do not hesitate to ask if you have any further questions!