Just out of curiosity, what does her comb and wattles look like?
Never mind, I just found your pic. Definitely looks like she should be laying. What a mystery!
Some info on internal laying:
http://dlhunicorn.conforums.com/index.cgi?board=diseasecasestudies&action=display&num=1169201098
Some threads here on BYC:
https://www.backyardchickens.com/forum/viewtopic.php?id=92569
https://www.backyardchickens.com/forum/viewtopic.php?id=85156
There's more...