Oh, okay I did not know that she had been off food already. Then her issue is either worse than sour crop or a severe case of sour crop.
I dont know, I have had hens that aren't free range that had 0 problems but then I had some that are not free range that had multiple problems.
I do not free range mine because there are too many hungry feral cats around here.
Maybe start off trying to treat sour crop. Take her off food for 24 hours, she can still have clean water in that time though.
You said her crop feels squishy as well?
How long has she been sick?
I believe that whatever your hen has, mine most likely has it too. Unfortunately she has been sick for over a month to no avail and she went downhill drastically yesterday.
What do you feed your chickens?
Do her droppings look like this? This is a picture I took of my sick hen's droppings today. She has a squishy crop, lethargic, her tail dropped, and no appetite. She is around a year old.