Thanks for the additional information. I didn't actually think there would be necessarily be open wounds but it might be helpful to see a picture of her face.
From your description, it sounds as if this poor kitten has experienced significant trauma. The fact that she's doing as well as she apparently is doing is nothing short of amazing!!!
As you probably already know, antibiotics will only be helpful if there's a bacterial component or secondary infection present. It's going to be difficult to know if this is the case or not but I would assume there might be. If so, then Penicillin isn't a bad choice although there is a fair amount of resistance to it these days. But it will be safe to give to a kitten this age.
There are a number of different penicillin drugs which are equally effective so much depends on what you have available to you. I'll list several in the hopes that one is what you have or can get.
Penicillin G Sodium or Potassium given every 8 hours
Penicillin G procaine to be given once or twice a day
Penicillin G Benzathine to be given every 5 days
The dose for anyone of these forms would be 20,000 units/kg underneath the skin.
I'm assuming that she weighs about 1.5 lbs, so the dose for a kitten this size would be about 15,000 units. As to how much this would translate into cc's or ml's depends on the concentration of the vial you use....units per ml or cc in other words. So, I'll need the concentration of whatever you use to determine the exact amount to be given in a syringe.
Penicillin V Potassium is an oral form although it doesn't appear to be readily available these days. The dose would be 10 mg/kg three times a day which means the dose for a 1.5 kitten would be about 10 mg which isn't going to be very practical since if you have tablets but would be fine if you have liquid at a concentration of 25 mg/ml. Then her dose would be 0.4 cc's or mls at one time.
Most patients tolerate Penicillins very well (especially if given as an injection) but gi signs such as vomiting, anorexia or diarrhea might be seen if given orally.
There won't be any other drugs which I would suggest at this point since any over the counter ones may cause more harm...the last thing I'd want to do.
If I was certain that infection wasn't a factor, then I might consider steroids especially if there's significant inflammation but to do so in the presence of an infection wouldn't be prudent or wise.
I hope this helps and that you'll continue to keep me updated about her progress. Deb