Hello Katie,
Your little ones are going to love
Jedi Training: Trials of the Temple! It's a completely immersive experience that allows younglings to use the Force and defeat the Dark Side. In fact, some might call it impressive, most impressive.
You are correct that the show lasts about 20 minutes. That said, once you have your show time, you'll need to have your child(ren) checked-in 30 minutes prior to that designated time. Make sure you keep the ticket you receive when you sign up so you know exactly when and where to meet. This time is used to gather everyone together, pass out robes and lightsabers and march to the stage. It's really fun!
I would advise you to plan about an hour for this experience to make sure you are totally comfortable and ready to enjoy this epic battle. Once the show is over and the children leave the stage, you are free to go.
I hope this helps you plan a fun-filled day at
Disney's Hollywood Studios, Katie! Check out the cool video below to learn about even more Star Wars fun!
May the Force be with you,
Andrea U.