Anyone familiar with Tincher Strength Training for pitchers? Age appropriate for 12 year old and so on.
I know one girl who lifted weights and wish they didn't because their pitcher is no longer 'long and loose'.
I respect people like Tincher, Boardmember, Riseball, Sparky, etc, for their knowledge about pitching. But, come one, they know as much about athletic conditioning as they do nuclear physics.
A skilled athletic trainers can get better results in a shorter period of time while teaching your DD the fundamentals of strength training. That is the kind of knowledge that will last her a life time.
If you want someone who really knows athletic training for softball/baseball, there is Eric Cressey.
Another myth...
Weight lifting coupled with flexibility training is the best way to build speed and endurance in any athlete. Additionally, girls don't bulk up like boys.
If the kid regressed, it is because she had a bad pitching coach, not because she lifted weights.