If she is drinking, give her vitamins and electrolytes. You are not an idiot. Many old timers used to feed their chickens corn or scratch, but it is not a complete feed. It may not be your fault at all that she is not laying. She may have a reproductive disorder. But she should be on layer feed as 90% of her diet, or you may give her Flock Raiser Feed with some crushed oyster shell in a separate container on the side. Flock raiser or all flock feed is used by many when you have roosters and hens, or chicks around. As long as she has the oyster shell, she will take enough as she needs for eggs.