Go easy on the sweetcorn, it doesn't have much protein in it and will dilute their overall protein and calcium intake.
Skinny says she is starving which means her body is not getting the nutrients it needs.... this may be due to a partial blockage (crop or gizzard impaction) or a tumour or possibly blindness causing her not to find food. Chickens will try to appear normal by pecking at food with the rest of their flock but if you suspect you have a sick one, watch closely because they will often pick up and drop the same bit multiple times or peck but not hit the piece of food....usually indicating poor vision.
If her crop is impacted she will be very hungry, but unable to eat much, which sounds like your situation and she will become weak because her body is living off it's reserves.... hence light weight and emaciated. Obviously she will not have enough nourishment to produce eggs. My guess from my own experience is that this has been an ongoing problem for weeks if not months. In my cases, the crops contained a soggy plug of tangled straw/hay and long grass that was preventing food from traveling down into her digestive tract. I managed to get one broken up with massage but it took over a week and the other it didn't work and as a last resort I had to do crop surgery, which was incredibly successful.
If it is her crop, I would recommend 10 minute massages 4 x a day, massaging from the bottom upwards.... she should enjoy it or at least find it beneficial. Sloppy food made from regular chicken feed (pellets or crumble, not mash) soaked in water and then made into a runny gravy with more water and a little olive oil mixed in and if you can get some "Nutri Drops" (they come in a small bottle with a dropper lid) from your local feed store, they will help give her some essential liquid nutrients. Some natural yoghurt mixed into her sloppy feed will also be beneficial.
If you are unable to get things moving after a few days, then you might want to try vomiting her but there are risks, so try massage first.
Or if this is a loved pet and you have the funds, find a vet because she is seriously ill by the look of her.