Woo hoo! Wasn't it fun? Sounds like she did fine for her first exposure. She might just need some time to mature a bit. Bummer about no pics, though!
Kind of simply put, and I don't know if I can explain it properly, balance means the dog is in the proper position to hold the sheep to the handler. So, if you move in one direction, the dog will move in the opposite direction to counter act your movement and keep the sheep grouped between you and her.
_________________________
Paula, Lilly, Jack & Alex