If she's a good softball player, maybe she should focus on that. I know ball players who also played basketball and track in HS, and they NEVER got a break. I can name at least two not even old enough to legally drink a beer who already show signs of having some significant physical issues that will affect them later in life. Breaks for athletes are important. Some running and weights in the off-season will do what's required to stay in shape.
Although TB in So Cal is pretty much year-round, during our brief down times, my DD's activities are letting her body recover and going to the park to hit bombs.