Be sure you’ve checked her for mites and lice. Checked her back end for fly strike this time of year, too, if you haven’t already. Simple things first, not to be overlooked 🙂
The crop is on her upper chest on her right side, it will bulge out as she eats and it fills with food during the day. It will empty at night and should be flat by the morning.
Azygous has given some good advice. You can get Corid at Tractor Supply or most other farm supply stores. Start there...
Based on the color of her comb, I don’t think she is mature enough to lay, either, but if you suspect she is egg bound, you can immediately administer a 600mg calcium plus D3 human vitamin tablet. Sometimes you can feel an egg in between her legs in her abdomen; I always struggle to feel this...