It was the sun filtering through the tree and through her dress that gave her that aurora of light on her hair and backs of arms. I did change my position as you described and the light I wanted was lost, I also did a series of her walking up the path from the gate behind her but it was that crucial spot where she is that gave me the effect I wanted, the other images from the set added shadows that were not to my taste. Even turning the camera from verticle to horizontal gave a different perspective and that light was starting to move away from the pathway very quickly, sometimes you have to go with what you have.