I'm really sorry for what happened. I was really pulling for the little adorable one to live.
I can't speak specifically to Black East Indies, but muscovys aside most domestic ducks are descended from wild mallards. Mallard mothers tend to lay 8-13 eggs. Even if they all hatch, she might...
If it still won't eat what @Jpat suggested, just put some sugar in water if nothing else. That might help keep it alive until it eats. Right now it just needs heat and calories.