Based on her symptoms,I would say she is an internal layer as well. The fact that she is not laying eggs does not mean she is not producing them internally. In my opinion, she is young to cease laying, which also makes me think they are staying internal likely causing an infection inside of her. If this is going on inside her, it is very painful and potentially drawn out. I would say it is time for a vet check to verify and put her at rest if necessary. I'm so sorry and hope I am wrong.
Jody
Jody