My simple addition to all the good advise is to pick at least some training days that have the wind directly down the runway. Your father should note that it is much easier to stay tracking down the runway and it is on these days that during a very good track, he should be coached into cutting the throttle and learning glide slope and ultimately letting the plane come down. No cross wind landings should be done until after the glide slope and landing flair are well accomplished.

What is wanted during training is focus on fewer issues, dealing with a cross wind and learning to establish a glide slope and dealing with a flair all at the same time is a bit much. Take cross wind out of the equation the first few times.