I'd have to guess she has some qualified disability of needing it to get around while at the event.
I know they only allow gas powered vehicles that are approved as Mutant Vehicles that must pass DMV before arriving there, Department of Mutant Vehicles.
They have many Mutant Vehicles turned down allowed in, since so many people apply and there is a limit allowed at the event.
Stand up gas vehicles (two wheels no seat) that are under some rated horsepower may also be allowed without need to have it considered a Mutant Vehicle.
I usually take the Subway while I'm there.... ha ha ha! There was a whole camp based on that. Nice try though.
Electric vehicles are another idea, but the motors and batteries I've looked at had high cost, had me not yet going that route. If I get something electric, I might try swapping out the Briggs 3hp 4stroke gas and still use the transmission gear down I already have.
MT