Amoxicillin is easy enough to get as Aqua Mox online for fish. Clindamycin or cephalexin might be good if it was a bone infection. But since there is no scab, it may be a sprain or injury.
I would limit her activity to see if her leg improves. Antibiotics may help if she has a joint infection with bumblefoot. Slings are helpful if they will stay in them and tolerate them, and not injure themselves getting out. Take her out often to rest and sleep. But they are great for eating...
Sorry that I haven’t kept up with your thread until now. Is that a bumble foot scab on her left footpad? Do you think the joint in her leg is swollen? She might be injured, but if her foot pad has a scab that might be why she is limping. Have you ever had Mareks in your flock before? That is...