I get this question a lot from my friends heading to Walt Disney World with their tweens. My answer is Walt Disney’s policy is 12 years and up but I then stipulate ‘it really depends’.
As everyone knows kids are all different. Some may be ready to spread their wings early while others may always want to stick with Mom and Dad (this can be good or bad). My recommendation is let your children be the judge and listen to your instinct. The good news is Walt Disney World is set up to give you children all the independence they could ever desire.