I find some responses to be mildly surprising. Yes, it's part of the game, and 98 percent of the time, hitting a batter is no different than a walk. No guilt. No apology. Yeah, it hurts a little. That's softball. Next batter.
However, I would not train a player to have no feeling at all. This isn't mortal combat. If a girl is truly injured and in significant pain for an extended period, I would expect my players to have concern or sympathy. Teaching girls that "She should've got out of the way faster'' and ''There's no crying in softball" encourages them to think their only purpose in life is to kick rear and not care about other people, IMO. There's a balance to be had.
We are talking 12 year old girls, not professional players with control. My dd is extremely accurate but on very rare occassion in her whole 2 1/2 years pitching experience has hit a girl. She needs to feel nothing but focusing on the next pitch so that it doesn't happen again. She has taken her share of rib shots and ankle biters in this game. She knows she has to move quick to get out of the way of a wild pitch. It is just part of the game.