How can one make sure that their child becomes an all-rounder?

You know my sister-in-law has this notion that one should be an all rounder in today's world and she puts that in practise on her son. She takes care of his studies part, as in, she teaches him and apart from that there is one season when he is learning skating then another he is in football team and in karate. She lets him be in a particular class for say 5 or 6 months the least and if he misses out on some classes, he would go in another and never loses the track of any one of them. Also, she is very particular in inculcating reading habits in him. She reads to him each night before sleeping. Introduces him to new authors. And shops for him, Books. She does work shops with and call his friends over, and they would make an origami book on say; Ramayan or Sachin Tendulkar, or Vand Gogh etc. So, he is aware of so many people, things from various walks of life. So, I think, one has to introduce children to various spheres and not limit them to just one or a few things.