Bullet spin when throwing overhand

[sprtfan]

My daughter is a pitcher primarily and has been pitching 1 to 2 times a week for months with no issues. Team practice started a few weeks ago and her overhand throwing has increased a lot. She mentioned this morning that her forearm was a little sore and I expect that it might be from the increase in throwing. When throwing, if she doesn't focus on it, she tends to have bullet spin on the ball. I saw somewhere that throwing with bullet spin can cause some forearm issues overtime. We'll take some time off, but wanted to see if that could be the issue? or is it more of just doing to much to soon. Any tips/drills to get rid of bullet spin? We focus so much on pitching that this hasn't been something we were to concerned with until now.