Hey J, I can understand your anger. Your Koi fish are beautiful! And to see the way they come to you in your video, I can tell how much you care for them.
I'm sure that little girl will remember what she did and when she is mature enough to realize how much she hurt you, I'm sure she will regret her actions when the light comes on.
Please forgive me for making light of your horrible experience. It was not meant in a mean way, really.