Sorry, this thread gets a lot of people who have no idea what a healthy ferment smells like (which can be pretty gross). I'm glad you know what you're doing. It's good to not feed a sick hen spoiled food. You might wanna try some scrambled egg (normally I would suggest raw, but why chance it with a sick hen) to help get her along. If she's still laying, mash the egg shell in there too. You could even mash some FF in with it. It seems odd, but an egg is perfect chicken food. You could also try some BOSS or moderate amounts of cracked corn. And electrolytes in the water (you can make your own with some brown sugar and sea salts). Good luck!