Have you talked to the rescue groups & no kill shelters in your area to see if they can take her in & have that properly treated? Perhaps a local vet will take her in as a clinic cat?
By the looks of it it's only going to continue bleeding etc and become at risk for more infections with the hay, straw, dirt she's walking on getting into it.
Avoid biting when a simple growl will do
The Spirit Lives As Long As Someone Who Lives Remembers You - Navaho Saying
Vindication ~ For all those pets who became sick or lost their lives from tainted pet food