Pushing the swing with the left hand, shooting with the right hand (trying to have a correct angle and timing), while she ask to go Forteeee! (with more energy, faster, ...).
Some technical aspects: there was low light, the sunset approaching. A great contrast between her and the sky and sun in the background. The autofocus was totally inefficient (too few light and moving subject) and I wasn't looking in the viewfinder (remember? I was pushing the swing!).
So I chose this technical approach: underexposure (1/200 sec instead of around 1/20 needed without flash), fill flash (attenuated nearly 2 stops), focus at half distance and shutter a little more closed (f/11); this gives me the possibility to have subject and sky both visible (compare with the only shot taken from high on her head) and a decent focus trying to guess the framing with the camera under my belt...
Two different process for all the shots: direct RAW/JPG conversion and JPG obtained from an enhancement of the original RAW data.
Comments, critiques, hints and tips are welcomed.