Why did my adult hen go broody and never resume laying?

[sstielst]

Hi-I have a 1-year old hen who is prone to broodiness. But in the past after she went broody she would start laying eggs again after 2-3 weeks. This last time, she went broody, stopped laying eggs, and hasn't started up again. It's been at least 2-3 months now! She doesn't act or look sick (doesn't have mites) and all of the other 5 hens are fine and continuing to lay. I have scoured the yard for secret egg deposits and I'm certain she isn't sitting on a nest somewhere.

Any ideas about this would be very appreciated!