Seemed to become the buzz word for the coaches and parents this year, from what I have seen the player immediately tenses up when they hear it.
Its almost impossible for a kid to relax on command. Athletes need to learn how to maintain calm during a stressful event ahead of time. You can't flip a switch and have a player snap out of it. Learning a ritual while in a calm state, will help a kid during a stressful time. My dd, we went through a couple of different scenerios on how to calm down and focus on the next pitch and not the last 1 (or 10). Its something you do in the barn and not in a game. Then instead of saying, calm down you can say. "Go to your routine. Trust in it"
For my dd I tried to get her to take an extra few seconds, clear her head have a positive thought and then go. Didn't work a bit, instead of clearing her head, the extra few seconds gave her more time to focus on why she was stressed. We then tried, you got the ball back from the catcher and you have 8 seconds to get rid of it. We did entire practices like that. She had no time to think of anything other then the next pitch. That worked for her. Now she pitches much quicker, games go much faster, and she has no time to stress.
Of course I am not saying this will work for everyone, what I am saying is. You have to figure it out ahead of time. Nothing you say or do during a game will make her calm down if you have not worked on it ahead of time. Find that routine or ritual that works best.
Sounds like it works for her, but you need a Plan B too, in case the other team starts taking time and tries to upset her preferred rythym. It will happen it it hasn't already!
Its almost impossible for a kid to relax on command. Athletes need to learn how to maintain calm during a stressful event ahead of time. You can't flip a switch and have a player snap out of it.