Beef liver is easiest to get. Is there salt in the cooked hamburger? She may need a little salt.
And, I did not mean to completely replace her food with hamburger and liver, but as additives. If she can't forage, she may need fodder/sprouted seeds. I'm growing some for my chickens.
Good for you, feeding species correct food. I am a predator raw believer.
I am not a nutritionist, but one hasn't answered so I will chime in.
Cats are different enough from birds that, I would stay away from cat completer for a chicken. I would give my hen bits of raw liver. Liver is...