All I know about chickens can be writ large on a postage stamp - and still leave space for "love, wish you were here, XXX" :-\....but I met Heldi's chickens last year and really got to appreciate chickens and hens, so I'm upset to read of your gal suffering. Do hope that it came down to too many baps & that a dose of salts or sommat has put her to rights by now? Anyway, all the very very best if you have to do the vet thing tomorrow.
love and a special cuddle for the patient, Lishka xxx