sounds like internal laying or some sort of infection in the reproductive tract.I was wondering that, myself. She hasn't laid since fall molt, and has passed these quarter-inch yellow things occasionally. There's a kind of puss inside them. Her abdomen isn't noticeably swollen. She was a regular layer last season, and laid the egg that is now my present rooster. In fact, that was close to the last eggs she's laid.
She's been on FF since the end of November.
It may just be her time, sorry.