Craig are you suggesting cutting/moving the pedal pads higher up the pedal arms??? If you shorten the arms it will make pushing the pedals harder as you will lose some of the mechanical advantage in shortening the arms. I would add material to leave them at the same overall arm length, but get the pads closer to the seat. I would think about 1-1/4" extra would help her get full pedal action without having to stretch the toes out fully.
How's the reach on the go-pedal???
