If this issue has already occurred twice in three years then it will almost inevitably happen again. Might be something to do with the way she is driving the car. If she does very little mileage and the engine stop/start system rarely works, then sitting on the brakes instead of shifting to neutral at traffic lights will create wear on the clutch pack. Better for her to switch to a torque converter auto, as is fitted to all Mazda and some Suzuki - such as the Baleno, Swift and Vitara.