Sounds like impacted/sour crop. It's possible that her vomiting has helped her to get some of it out. What does she eat? Have you watched her eating? Does she eat grass or lots of greens? I'm not an expert on this problem but I'm sure someone here can tell you. There are certain foods you can give her to assist in her passing whatever is stuck in her crop.
I would do the opposite. Grass and leafy greens are known to cause an impacted crop if she's not eating enough grit to go with it. I'd withhold anything green until it either passes through or comes up. You can try to massage her crop to get it to move too.
Thank you HenHouse. I'll throw more grit down. I was thinking opposite - too much scratch and lay mash. I'll try the massage thing on her and see if she can spit it out. You are a great help to me and much appreciated.
Some yoghurt may help to introduce good bacteria into her crop. It won't hurt to try her on some of that. Scrambled eggs are also a good source of nutrition when they are unwell.
I agree it sounds like sour crop. Is her breath bad too? I would keep her off the long grass for now, and don't give her whole wheat or scratch either. It can go rancid in a sour crop, and make the situation worse. Her pellets should be fine, but she may not feel like eating much until her crop clears.
If she gets lethargic or stops eating entirely you may need to seek veterinary assistance. I don't mean to frighten you but once sour crop takes hold it can be hard to bring them back from the brink. Not impossible - just hard. They can lose a lot of condition as they are reluctant to eat much.
I lost a hen some time back because I left it too late to see the vet. I also had one girl with an impacted crop and she was saved with surgery.