OK, you've done all the right stuff so far
Keep her separated and warm. She is probably in shock, and may not eat or drink for a little while. Syringing fluids into her is good.
Make a warm water solution with molasses, it has sugars and other good stuff in it. It will give her a bit of energy and vitamins. If you have any B vitamin capsules or tabs, crush them up good and dissolve in the water. Keep doing that every couple of hours and then leave her be to overcome her shock.
As far as her head goes, cleanse the area with soap and water. Clip back the fuzz around it to keep it clean. Then put on an antibacterial cream, neosporin will do.
Chickens are remarkably tough. I have one right now, a four month old, who has NO skin on her back, just a big nasty open spot I slather with cream and I keep her warm and quiet in the house. She didn't eat for a couple of days on her own, then started in and I still can't believe she's alive.
The chick's biggest worry is having other chicks peck at her wound. Once it seems to have scabbed over, put some BluKote on it (at your feedstore) it is a drying antibiotic ointment for livestock, and it stains the wound blue, a color other birds won't have the urge to peck at. She will have a goofy looking head for a while, till she feathers in but at least you'll be able to tell her apart from the others
If she doesn't make it, it's probably because she got some brain damage, and there's nothing you could do about that but what you are doing already.