i would suggest taking her to a pitching coach first and maybe after she learns techniques than when she goes out on the field maybe it will open her up more

Build her confidence and you will find a winner in a lot of things! Give her the tools to practice. Set up things for her that gets her mechanics down on her own. Sign her up for some 1:1 lessons with a good instructor! This will build on both. Plus, she is in the light! In addition, nothing counts for game time. Get her in a position where she is getting to pitch a couple of good innings and ask the coach to move her. Yes, when she is good! This will allow her to have some good game times and not associate getting pulled with bad pitching. We all get pulled every now and then.! She will love it once she gets the itch!