Go for the AAA parking. Even if it's full, you'll probably be glad you have your car. They pack those busses mighty full at the end of the day, and depending on DW's tolerence level, she might feel really uncomfortable and stuffy.
Even if you do have to park further away, there are trams so she won't have to walk all the way from the car to the gate. And if she gets nauseated she's not going to want to get on a bus and endure all those stops.