Sick Choog; white diarrhoea, lethargic and pale skin

[Oolala]

She may be having some reproductive problems, hard to know.
If you don't have much time, then all you can do is try to make sure she's got access to fresh water and food.
If she declines further, then do your hen a kindness and ask your Dad to put her out of her misery.

What about trying the epsom salt bath first and some massage, you have nothing to lose, it will not take that long to do, its worth a try