What you might want to try, is Meditation.
I don't mean the purist sitting for hours kind of meditation.
Just sit, with legs comfortable, and everything quiet, and close eyes, and focus on a relaxing or happy mental image. Even if for 10 minutes. Or whatever your daughter can do.
It is a process. In time, a person can do it for longer.
And while doing it, concentrate on breathing... from deep in your gut, and expelling the air. In a rhythmic manner.
And YOU do it, WITH her.
My daughter's Kindergarten Teacher, 'taught' her kids this, and did it with them in class, in the afternoons. They LOVED it. It helped to get them centered and more peaceful.
My own daughter, (who is 8), LOVES to meditate. Even with the Wii.
She even does it with my Husband. Who practices deep breathing and meditation... for overall health and well being.
Or, Tai Chi, is also a GREAT thing. For all ages.
all the best,