Do you know whats wrong with my hen, dropping photo included

[Dbaas]

posted a couple days ago, she was having issues after foraging in our backyard. she laid a thin shelled egg, scoots backwards everywhere (although she seems to be walking more and more, albeit unsteady on her feet),her droppings were foul smelling but the smell is gone from this one. I've given her apple vinegar, massaged her crop after dropper of veg oil, warm sits bath, and one dose so far of antibiotics yesterday (more later today).

I hope it is not egg peritonitis. Theres nothing i can do for that is there?

thanks for looking, advising.