Steve,
Looking at the picture, I would think that she has not ovulated yet. Her spine doesn't look as pronounced as most females that are carrying eggs. Are you sure you witnessed her POS? Have you palpated lately, and felt follicles or eggs (softer than eggs)? I am not trying to question your experience level, but just commenting on something that I did my first season. I had a female that was 100 days POS, but when I got her ultrasounded, there were no eggs, just big follicles that she never laid.

Good luck with her.