Lost a hen

[Wolfie2]

Yesterday. Found her stiff, dead, on a nest sittin on 4 eggs. Did not find any injuries, no one has been sick and she was only 1.5 yrs old.
Only thing I could think of: Barred Rock. I have 3 of them. Had 1 that I tried to discourage from setting for about 2 months then out of desperation i went ahead and let her hatch a batch so another month give or take.
The young'uns are now about 2 mos old. Don't know if this is the hen that hatched the eggs as the hen has left the pullets to themselve for 3 weeks or so. If it is the same hen, Maybe I weakened her by prolonging the "incubation" period for so long. she has been off the nest for almost 2 months now and seemed fine, now this!
Any thoughts?

 

[Wyorp Rock]

I'm sorry about your hen.

Without a necropsy, there's really no way to know why she died.
If you still have the body, refrigerate it and send to your stat lab. https://www.metzerfarms.com/PoultryLabs.cfm

Another option would be to do your own informal necropsy to see if there's anything obvious. Take photos and we'll try to help you with what you see.