I hope she didn't feel pressured to euthanize it because she felt guilty. I wish I had found the thread sooner.
The injury honestly isn't much worse than some of the commonplace chick pecking incidents. And it seemed so full of life.
I don't mean to commandeer this post, but I am in a similar situation and am eager to hear the outcome.
I had a broody hen hatch 10 chicks. On day two I had another rogue hen sneak in and badly peck two chicks through the wire separating mama and babies from the rest of the flock. We are on day 7 now, one injured chick died this morning. She had a throat injury and couldn't ever breath properly. The second injured chick is still alive and seems perky despite a bad head wound and I can't justify euthanizing her. She is eating, drinking, and pooping.
But now I have a problem...I think she's lonely. She makes that alarm-peep noise much more frequently and seems agitated. I tried reintroducing her to the brood (TERRIBLE idea, mama almost killed her). I've considered taking one chick in to keep her company, but if my injured chick doesn't make it I'm left with another lonely chick that may be rejected by mama if I tried to bring her back later. I don't know what to do, I've put some beanie babies in the brooder with her (maybe that's a terrible idea but I'm desperate). She just doesn't seem like a lost cause and I want to give her a fighting chance...but I don't want her to suffer physically or emotionally either.
So, I am interested in the OP's situation and what she did with the chick during recovery? Any thoughts on the loneliness during recovery problem?
As the OP hasn't said anything yet ... I don't think it's that the mom has rejected her baby. It's just that chickens can be really savage, bloodthirsty things. As long as the chick has any kind of wound, you can not give it back to mom. You also have to be careful of the other chicks as well as they might also go for the wound and peck at it. What you can try is take one of the other chicks and keep it with the injured one. If the other chick does not go after the wound, it will be company enough. The injured chick will also cry if it's not warm enough. If the heat is ok, buy a fluffy feather duster and hang it in a corner of the enclosure about 3 inches off the bottom. The chick will snuggle into the feathers and feel a lot safer and comforted. Don't put neosporin on the wound. You need to allow it to dry and scab over.
If you put another chick in and it works, keep them together until the wound is no longer visible. You should then be able to put them back with mom. It's not that mom is rejecting her chick, it's a wound and it won't matter if it's her own chick or another hen. It's just what chickens do. If it doesn't work, return the other chick back to mom. At night if you prefer it. She will be fine with her temporarily absent baby. Your chick only has a head wound and is acting normally and will recover. The OP chick had the skin ripped off it's entire back which for a tiny chick is a huge area (about half the skin of it's entire body). There is a very big difference in the extent of the injury.