Let me echo Amy's comment the catcher in the OP and PC post both 10U and take several step and a windup for a reason, I simply do not know many 9yr olds with the arm strength to get the ball to any base using what we would call proper technique. OP catcher will throw most girls out with a throw like that and as Amy said about twice is all you need for them to stop running.
Usually I would advocate going with proper technique for any skill over getting the job done because eventually your poor technique will become a habit you can't break, this however is the exception. There is no reason to sacrifice an out and as PCs post shows you can get outs for technique. Once the girls gain the arm strength you could break the habit very quickly because the girls now don't need the poor technique of extra steps to get the ball down because they can compensate with a more powerful throw.
Yep... the story is that DD is the #2 or #3 catcher on team. She was filling in because of injury to catcher. End up going 5 innings that game, and her first full game, the Championship that Day. She's just the one for 3-4 game loser bracket day in the heat of the summer...She was told after tryouts she wasn't as polished as the catcher... :{))