I agree. Of course there are are always exceptions depending on game scenarios but at 10u you want to get the sure out as much as possible. And also don't assume these girls know where to go with the ball before each play. Make sure infield and outfield know before each play what to do and where to go with the ball... It's the same with baserunning. Before each pitch remind them of how many outs and what to do if its a passed ball, hit on the ground or in the air or if its a line drive.
Also... probably the most important thing is that the girls should be learning and having fun. It's 10u. They will without exception all make an error or strike out or swing on 3-0. Don't get upset with them. They should be learning to enjoy the game.
You probably should have a pre-tournament talk with the parents. There will be a lot going on during games, but make it clear to the parents not to shout instructions to their DD during the game...just cheer and leave instruction to the coaches. In my admittedly limited experience I find that some parents new to travel, usually at the younger ages, tend to be the hardest on the kids as they haven't been around enough to realize its not the end of the world if their kid or another kid makes an error. They are fresh from rec where DD was a superstar, usually the loudest and constantly screaming instruction to their own DD and quietly (or not so quietly) bad mouthing the other girl that made an error that caused a few runs off their DD. One that irks me is when the pitcher's parents scream out to their DD immediately after a fielder makes an error, "It's not your fault honey! YOU are doing great!" The more experienced parents are usually the quietest and if you didn't know them you would not even realize who their DD is. They sit quietly and cheer appropriately.
