As with all things remember progression is key. Don't start your plyo regime by dropping your daughter off of a 6 foot box. If you start with lower intensities and gradually progress the intensity and volume she'll be fine. For example, adding deadlifts, squats or cleans could be very beneficial as long as you start at an intensity which is appropriate. The same (as Danimal pointed out) goes for plyos. Sprinting actually places great stresses on the body and if she can already handle those stresses and run as fast as she does she is definitely ready to handle some form of weight lifting and plyos. As others said though, don't neglect general fitness work though because at her level this will be where most of her gains will come from.