pozees2
Crowing
Excellent advice, hydration is key to almost everything.With her age and laying rarely, not being able to roost and having trouble walking/roosting, not wanting to stand and is being attacked - I would be inclined to say she's got some type of reproductive problem going on.
I would try to get her hydrated. If you have them, give her a direct dose of poultry vitamins. Once she's drinking, offer her a bit of wet feed.