It is hard on the spider gears in the differential also. I saw a Honda hub carrier all 'wore out' due to significantly different diameter tires used on the front end..... for 10's of thousands of miles. Those little gears were just not designed for those kinds of rotations....
My favorite though is someone, usually a 'soccer Mom' or similar, bucking his / her way through a turn 'cause the grocerie- getter is stuck in 4WD.
I have noticed that auto manufacturers are continuously 'dumbing down' 4WD into "AWD" and "Full Time 4WD" and various other incantations of [not real 4 WD] mechanisms. I just picked up a GMC Envoy but not after looking at a bunch of recent year 4WD vehicles that either were not really 4WD or were but did not have a low range.
Brian
Hopefully she didn't have traction control or had it turned off. Otherwise it would destroy the brakes.