He’s saying she should have a tag that hangs on the rear view mirror that can be put on your car when you drive her around (as opposed to a handicap license plate that can only be used with her car).
In my country only the car owner can apply for a disability permit. I’m the car owner, she doesn’t even have a driver’s license.
In my country a disabled person can get a tag that they hang in whatever car they are in to mark that car as able to use a handicapped space - they are expected to switch that tag between cars when they get a ride with someone else.
If the handicapped person owns a car they can also get a special license plate on their car thus ensuring they don’t have to keep track of that tag.