Yes, training the wifey can be very testy. The first few sessions ended with her being mad at me. What i learned was to correct/critique only one problem. First we worked on keeping the back arched, then it was depth, then it was knee position. Finally it was try to put all that crap together. It has taken over a month to get a decent squat, and the depth is decent, but not great.
All the other lifts have gone well, but the squat was hard. Now if i could just get her to eat enough to get strong.......guess i'll start with breakfast, then lunch, then milk.......probably take a month. lol