We are going out for a couple of sets this afternoon and I will try to get her on a more forgiving ski for the 2nd set and see how it goes.
We have a handle set up in the garage and when she leans on it her position looks OK, nothing like her on the water position, but I will definitely try the tug of war thing with her and yes I think she could do with some strength training.
As for coaching I am just taking an interest at the end of the season (I know the pitfalls after trying to teach her to drive a car many years ago), but she normally skis with the other coaches and her friend at our ski site, my on the water input is probably about 10% but I do try to talk about it off the water, would probably help if she was more of a ski geek like me.
We had planned to do a lot of free skiing this summer but that fell through due to the reliability of the boat at the club we were going to do some extra skiing at, but they are getting a newer boat for next season so fingers crossed we can get more quality water time next year.