If she had egg yolk leaking from her vent, then she likely had a membrane break inside her. She may have been able to expel it or not, hard to know unless you saw her do it. A soft shelled membrane would have been quickly eaten by other hens.
IF she has yolk leaking, that's a perfect medium...
What is that on the towel? Poop or something leaking from the vent or ???
How do you know the hen has EYP? Usually a hen with EYP can be lethargic, act like they are egg bound or hunched up. They may or may not have bloating or a swollen abdomen. EYP is when the yolk or egg material has...