There is a learning curve with a
scooter. You are dealing with a crowded park for one. You can have kids that dart out right in front of you, for example. You have to be alert and have quick reflexes to stop. It's best to try and surround the scooter; so, she has a little buffer.
Then, the ride queues have twist and turns which has to be navigated. There's a couple of rides like Soarin' and Living with the Land in Epcot where you need to use an elevator to get the scooter down one level to those rides. You can skip those rides or have someone else do the scooter for the elevator.
You might want to practice at the local grocery store with their free scooters. Also, once you get the rental scooter then practice, as well before going to a park.
You might even want to visit a local mobility store and get a demonstration on how to take it apart and put it together. A Victory 10 is a pretty big scooter. It's heavy. One battery weighs 30 pounds, for example.
To conserve battery power make sure the scooter is turned off when watching a show, movie or fireworks.
Make sure you charge your battery every night. Watch your battery guage at the park. If you are running low then you will need to find an available outlet to charge the battery. You may want to ask a cast member where the best place would be to charge up for a while.