I thought it was 3

I think it is coaches discretion isn't it

Dawn is right at least in our township we have the coaches ruling, but remember factors if the pitch was thrown on purpose (which has happen) the umpire can eject the pitcher, the league officials can also make that call but if accident you could talk to the pitcher and get them focused, if happens again I would pull the pitcher. ( We are a fun league, but have strong standing on safety)

i dont believe the IHSAA has any rule about taking a pitcher out because of hitting so many batters . ultimately i think it would be the coaches choice

As the others said, it depends on the league. In some youth leagues a pitcher must be removed if she hits 3 batters. In other leagues there are no rules that mandate removal from the mound.