She a car driver? When my girlfriend's Jetta broke down I had to share the Path with her and I did notice that car drivers will accelerate towards a red light and then just jam on the brakes like gas still cost a $1.50/gal and we get 30mpg. I'm up to 45k on the original pads and rotors but have had to shave the rotors every 20k.

Sounds like it's time to yank gradma's license...
I can understand wearing out a pad fron the Ebrake being left on. But since the Parking Brake is actually a drum within the rotor I don't quite understand how it could lead to a caliper faliure.