I'd definitely keep her away from the boys and maybe the hens too of they are bothering her. Do you have any Vetercyn you can spray on her? Other topical antibiotics will help too. I had a similar situation years ago and didn't have saddles either. So I put the girl in a crop bra, loosely, and...
They definitely mourn their buddies, and the mourning period can last quite a long time. I had a hen go 3 months after the loss of her sister...., depressed, refused to free range, she stayed on the roost bar all day, stopped eating, laying, went silent (she talked constantly) she would stand...
I'm glad she is feeling better! I had a hen that started having trouble putting a hard shell on and would pass yolks and soft shelled eggs. But she occasionally would get very sick looking especially when these soft shelled eggs took too long to pass. If your girl is having trouble, you might...