If it were me I would lock her up for a couple of days to find out for sure if she's laying or not. Really if they have access to the great outdoors there's no guarantee you're gonna find eggs they lay.
Hmm, that's odd. Is she completely confined so you know she isn't laying?
I wouldn't necessarily be concerned yet unless she's showing symptoms that she's distressed in some way, but she certainly should be laying eggs by now. 🤔