one of these daily hours should be in a private or semi-private with a world-class coach.
We know that the best coaches tend to be parents, as long as they know what they're doing.
One anecdote, I grew up with Andrew Sznajder (46 in the world at one point); his dad was his unique coach. A mediocre player and not somebody who knew all that much about tennis. However, he would spend hours a day feeding Andrew tennis balls and establishing drills. What kids need is not tennis lessons but to hit lots of tennis balls (i.e., practice time and matches). It makes me sick to see parents spend a fortune on lessons by unethical, money-grubbing coaches.