My daughter has taught many to ski at our little lake in MA. She is of course not available to teach others unless they are visitors.
We all learned with persistence and a very patient driver. We all learned to be very patient drivers, often pulling skiers for a couple of hours.
Sit in the water about waist high give or take a little.
Pull your legs to together, knees to the chest, ski toes above the water pointing up
Hold your arms straight out holding the line handle
Have someone hold your skis together as this is hard at first. I think this is where the trainers may help a new skier. We used to have a swimmer in the water holding the skiis together swimming out when the newbie fell. This was hard work.... but all did learn to ski and get up and eventually could hold their skis together on their own!
Let the boat pull the line out until it is taught, then shout , "Hit it!"
When the boat pulls, let it pull you, do not pull back or you will fall backwards, do not lean forward or you will fall forward.
As the boat pulls try to stand up so that you butt is not being dragged for long or you will get very tired very soon.
If you keep falling, stop and rest for a while and let someone else try, then try again after 10 or so minutes.
For the driver: drag the skier for a few feet then go faster. Do not go fast all of a sudden with a new skier, do not drag too far or they will fall. some drivers are idiots.
Once the skier is starting to get up go just a tad faster so they do not fall over sideways. Try to go straight for a while as turning the boat with a skier just getting up puts more slack on the line and they will fall.
Teach the skier the hand signals that you use. I also teach the signal to stand up straighter. New skiers tend to lean too far forward. If you have a signal to stand up straighter that will remind them. Use this only once the skier is up and hanging on well.
I was 10-11 when I learned to ski. We tried to get my daughters up from the time they were five, but I think they may have been older when they got the hang of it. We finally bought junior sized skis which helped a lot. My sibling's grandchildren are all tubing which I think keeps them from learning to ski. We did not have wakeboards so never learned how to use one. We did have a disk which was a lot of fun.
Many, many years ago when I was a teenager, our neighbors had guests from another country. The loud and boisterous female guest wanted to ski as she claimed to be an expert skier. We laughed for an hour as she stood up in the water, chest high, skis on the ground and had the boat try to pull her up. At one point we suggested she follow the above instructions but she insisted that her way was the right way... she never got up.
I hope your little one has many enjoyable years of waterskiing!
IG