Coach723 is right that the exudate inside her vent looks similar to lash material. She might have salpingitis and be laying internally. If you remove some of that material I would cut it open and take pictures. Here is what lash material looks like...
It looks like a chronic constipation problem in the picture. She may have been pecked around her vent or had too large of eggs or a prolapse that has caused damage. I would,soak her vent in warm Epsom salts or soapy dishwater for about 20 minutes a day. Put on a disposable glove and insert a...