That may be a mile from the terminal!
"Well Mom, you need exercise anyway. Drag one, and put one on your shoulder, and can carry the other bag in your left hand. And I'll meet you right here Sunday at six PM."
(Just kidding.)
Just drop them off at one of the car rental locations and let them take the bus to the terminal.
Of course, that's only good if the facility is not inside one of the terminals.