You keep at it until she doesn't want to do it. We had a player a few years back on our 12U team. She was the only 12 year old with all really good 11 year olds. Never pitched an inning. By the end of 14U she started pitching some and now pitches for a mid D1 school. She did happen to have some physical gifts in size but still she went from nothing to D1 in a few years.