1997 Nissan Elgrand brakes wearing out within 3000 mls

My daughter bought this used Elgrand 3yrs ago and is generally pleased with it. BUT on the first MOT it failed on Front brake pads, discs and calipers. The test was done at an MOT only garage so it was probably correct. She had the work done and it passed the MOT. The following year it failed on front pads, discs and calipers again, we took the car back to the repairer but they had closed down. We decided to cut our losses and have Kwik Fit do the job and MOT it themselves, all OK then. Now 14 months later the pads were grinding, took it back to Kwik Fit who said it needed new pads, disc and calipers on the offside only. After less than 5000 miles. When asked why Kwik Fit said "no idea why" This will be the 3rd new disc and caliper and the 6th set of pads within 13000 miles. She only uses her right foot on the brake and doesn't ride the brakes, has anyone any ideas as to the cause of this please