Lots of times, the best training tools can be home made, if done properly. Of course, it depends on your instructor what they prefer you use. Some things my DD used over the years:
* Striped ball to show spin direction (a black marker works fine)
* 18" PVC pipe for rope/weight rolling (forearm strength)
* Surgical tubing hooked to weight belt (used for resistance training)
* Popcorn can filled with rice (finger/wrist strength)
* Nerf size football (for spin)
Good pitching starts with good physical conditioning - ESPECIALLY legs for women. The pitcher is the most physically active player on the field, and cardio training for endurance and leg strength are often overlooked. In retrospect, I would say that just being in excellent physical shape is half the battle. Most of the rest of the specific skills can be taught through many thousands of quality pitching repetitions. The toys may help, but there is no substitute (or shortcuts) for quality repetitions.