DD had this problem in her second year of 10U. It seemed like every game she got plugged, and she started stepping out. We bought her an elbow guard and taught her how to get hit. I threw a lot of front toss to get some confidence building back up again. Try putting something behind her front foot (helmet, bucket ,bat) so she can't step out. It takes time & a lot of reps. Getting hit is no fun, but it's part of the game. Eventually with my DD the will to succeed overcame the fear of getting hit. Now she stands practically on top of home plate and getting hit by the ball is not in her mind at all...at least that's what she says lol.