Thanks both.
The other girls seem sad too and the pecking order has to be rearranged, so there is some jostling too.
I am not sure what she died of (hopefully just natural causes), though one of the girls now has a dookie butt and floppy comb (hopefully just a bit of stress after the loss of her pal). But I'm keeping an eye out to make sure the rest of the girls are okay. I've upped the cider vinegar in water and added poultry spice to the food.