If iodine is all you have, i was thinking neoisporin or triple ointment if you have it.
How is she acting? You know she may have internal injuries. Just keep her comfortable. Is she eating and drinking?
If it was a preditor bite, it will likely be back. Is the rest of the flock secure?
I hope she recovers, i love speckled susex.
I wrote a story in the story section of BYC about my favorite hen Spot, who was this breed. I had to take spot to the vet ( the subject of my story)
You may also concider the vet, but not all vets treat chickens. I had one vet tell me i "should put the potatoes on to boil".
I ended up treating my bird myself and she made it.
Please keep us updated.