I am wondering if the original injury was a bullying that was brought on by too small of quarters. Do not put the victim in the coop with the other two. You could try, putting the mean bird by herself, IF the other two get along.
Do know:
- That being raised together has no effect on overcrowding
- that what was enough room when they were chicks, may not be enough when they are full size
- a couple hours of free range does nothing to help over crowding
- pre fab coops vastly overestimate what can live in there.
mrs k