Not sure if the recent posters checked your original post and photos, but your hen's at risk of permanent deformity/lameness/failure to thrive. She's already having difficulty walking. She needs a vet or your best attempt at being a vet.
Treatment for SLM has been extensively covered on...
7 or 8 days per this site: https://justagric.com/ivermectin-for-chickens-egg-withdrawal/
But I've also read there's no withdrawal. Since it is an "off-label" use for poultry, we don't have the specifics from the manufacturer.
It's a long process to heal, there is no instant fix. Since SLM have a 10-14 day life cycle, even if you kill them, the eggs will hatch and they'll come back. I tried all the vaseline/soaking/AD ointment but it's very messy and I didn't see any results after about 3 weeks so I applied 5 drops of...