Good morning.
Measure those butt bones by placing your fingers side by side between them. If your get two fingers between them, she has been laying. If only one finger fits, she hasn't ever laid eggs yet.
Back to the crop, yes, I agree that her problem may very well be sour crop especially since she vomited a bit after you got through feeling around it. Do what
@rebrascora describes and massage the crop. If you feel some solid, hard matter that won't soften after massaging it, try some solid coconut oil on your finger. She may eat it off your finger. If not, swipe it into her beak. Try to get a full teaspoon into her. Massage again. If the hard mass still doesn't break up, repeat with another teaspoon of solid coconut oil and more massage.
Next you will need to treat the sour crop. The treatment is miconazole. Can you get to
Walmart? You need to pick up a tube of vaginal yeast itch cream. Get the cheap stuff. About $5. You want to squeeze off about half an inch onto your finger and get her to eat it. If she won't take it off your finger, open her beak and swipe it off your finger just inside her beak.
Do this twice a day for seven days.
You can let her eat some chopped boiled egg. Maybe some grated raw carrot. But no bread or anything starchy. The sugar feeds the yeast infection in her crop.
She will begin to feel better after a day of treatment, but keep it up twice a day for a full seven days.