Thin hen. Should I be worried?

[Soot the silkie]

So last summer I had a pulley die suddenly in her sleep. Leading up to this, she was very thin. Now one of my hens also feels super thin, i.e. no fat at all on either sides of the breastbone. She was never really fat but now it's worrying. Is there any correlation between the two? Or is she just thin from increased daylight and more egg laying?

 

[Pork Pie]

If its not a flock dynamic / food access issue, i would at least worm her (all the flock), pending advice from the experts.

CT