Please provide info re: the below questions (posted toward the top of of the emergencies section) so folks can better help you. Add to this any info about egg laying (when was the last one, was it normal, how often does she usually lay etc.) and literally absolutely anything else that could provide clues. @What is her diet? Any new coop mates? Etc.
I had a hen go lethargic like this last fall and with the right meds (antibiotic, antiinflammatory) she was better very quickly but lethargy can mean many things. Without prompt attention I am certain my hen would have died. They will hide their troubles as long as they can - by the time they present like you describe, it is an EMERGENCY. And you say she saw her like this the other day - a lot of time has passed in chicken-time.
Unfortunately I won't be on this site much until late tomorrow (it often stays minimized on my screen when I am not around) so keep providing info and updates so others can see your posts and help.
1) What type of bird , age and weight.
2) What is the behavior, exactly.
3) Is there any bleeding, injury, broken bones or other sign of trauma.
4) What happened, if anything that you know of, that may have caused the situation.
5) What has the bird been eating and drinking, if at all.
6) How does the poop look? Normal? Bloody? Runny? etc.
7) What has been the treatment you have administered so far?
8 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet?
9) If you have a picture of the wound or condition, please post it. It may help.
10) Describe the housing/bedding in use
JJ