A shell-less egg is very hard to pass, and they can become egg bound, but also that can be a sign of a reproductive infection. Can you offer some calcium, in a calcium tablet, Tums or calcium antacid, or pulverize a hard egg shell and feed it to her in some cooked egg? Calcium deficiency can be a problem, and it may help her pass an egg. Look for any yolk or albumen (egg whites) in her droppings.
Gatorade or Pedialyte are good sustitutes for electrolytes. And you can find homemade recepipes online for chickens.