I agree-at least 14 days of antibiotics, plus that foot needs a debridement by a vet. (it's soaked and the dead, hard skin and scabbing needs to be scraped off) she may have some gangrene under there which needs to be removed as well. She needs a topical antibiotic as well. Poor girl does look uncomfortable, but pretty healthy otherwise. The smell sounds like gangrene. The smell is unforgettable, and it will permeate the entire body from the affected part.I think she will need antibiotics for longer than a week, with that severity of an infection.
I didn't notice the spur at first, I bet if that got trimmed shorter, it may make it easier for her to walk.
I have had some birds tripping over their spurs, unfortunately, trimming is necessary.
Just try not to cut too short, as she already has sores.
I use a doggy nail clipper, and just cut small pieces away at a time.
(I'm no chicken expert by a long shot, but that's what is done with situations like that in other farm animals, and humans as well)