Are they true purebred Araucanas (rumpless) or are they hatchery chicks? If hatchery birds ( hatcheries might call the Ameracucana or Araucana but really the are Easter Egger or "EE") I would say to start looking for eggs around 20-25 weeks old, depending on what season it si when they are that age (i.e. if its the dead of winter it might take longer).
If the are EEs they've been cross-bred for better egg production, most likely.
If true purebred Auracanas, I think you're right and they don't lay terribly prolifically... there's someone on this board who breeds them who might be able to advise...
Good luck!