There is a fine line between pushing a pitcher to be the best she can be and pushing her over the edge. I have seen it go both ways and the "line" is different for everyone.
^^^ THIS!
If you find yourself as a parent, nagging and pushing your kid to practice, on a weekly basis;
then that is a strong signal that it is time to back-off.
"It's a marathon, not a sprint" mentality is so true, especially 14U and younger.
You don't want to drive a kid away from the sport.
Give them space. Still lots of time for that internal fire to ignite on it's own;
and the relationship and experience will richer.