How long ago was it when you wormed, and do you know what worms you treated for? What did you use?
Have you checked for other parasites like mites or lice? How old is your hen? When was the last time she laid an egg?
Forcing calcium can be bad, I wouldn't do that UNLESS she was egg bound. Usually death occurs within 48 hours, so that probably isn't it.
What do you feed normally, including treats and supplements? How many in your flock? What size coop/run? When was the last time you added new birds?
When you saw her wobbly and with diarrhea, was she also standing up sleeping? What color was this liquid poo?
Any chance you might take a fecal float to the vet for about $15 they can check for worms and cocci to make sure if she does need to be treated for either. (I know today is Saturday)
You should be careful pushing too much food on bird who is not well. You need to make sure that the crop is not impacted. Are you providing any sort of grit for her? Possible sour crop? What have you looked into beside cocci? And IF it was cocci, maybe treating correctly will help...
IF and ONLY if you are sure you haven't overdosed her on electrolytes (because that can be VERY deadly) Then I would give that solution with boiled egg, as you are trying with the kale & sweet potato except eliminating those as already suggested.
As a last ditch effort I would give raw egg yolk. It's loaded with the vitamins, minerals, and micro nutrients needed to sustain life as well as easy to digest! Don't push anything chilled though.
