I agree with Eggcessive. You may want to look at this thread:
https://www.backyardchickens.com/t/79443/tell-me-about-your-internal-layers/80_20#post_6235380
I wouldn't check her for being egg bound, either, since she hadn't layed for several months. In the pic it looks like her abdomen is swollen and would feel fluid filled if handled. is this the case? If so, I'm afraid the likel explanations are not good, like cancer or internal laer.