Hi Eileen -- yes, I did know about this entry on Find A Grave. The actual researcher of this soldier had told me.
I suspect the biographer of deceased Darwen soldiers is NOT going to be able to get further back with Andrew Kenny, unfortunately. We know nothing about his birth or parentage with any certainty, despite everyone's best efforts.
I so want to thank ALL OF YOU who have spent time on this query - I really do appreciate all you have done.