Thanks for the advice. The chick is still doing well, but we have a full on summer storm today and it's absolutely **pouring** and won't stop. I'm sure my little lady has her wings full keeping the other chicks warm and as dry as may be, and I'd get soaked monitoring the situation. I'm still really wondering what happened. Can a mother peck a chick's skull so hard it causes a brain bleed? I see no symptoms of illness.
I'm tempted to let it mix with the chicks I have inside, which are all the same age anyway, but what if it goes backwards? What if it is infectious afterall?? I gave it a mirror so it can see itself and feel a bit less lonely but it's still pining for company. I can't shake the image of the poor little thing just lying there limp with quite a bit of blood all over its head.