After meeting Tina Maze, Marcel Hirscher and Ted Ligety at the Levi WC in 2014 he got super inspired and motivated to ski like them. He started to assist ski instructors in the local ski school and worked on his OLF retraction turns whenever he could. He quickly developed into a very strong all mountain skier.
Then suddenly at the age of 15 he got interested in ski racing again and the following year he got proper skis, boots and a speed suit. Rock'n'Roll! Went from the average Joe to great in one instance. He is easy to coach as he does what you tell him to. He is also super motivated and spends much of his spare time studying racing technique, mostly here on YouTube. Out on snow he does drills all day long. Check out the 14 Essential Drills For Ski Racers https://up-tube.com/upvideo/LqUaTAme2hj as a reference.
Be patient. That is all I can say as a parent and a coach. Let the kids have fun and they will surprise you!