Woohoo!!!!  7 eggs from the young ones for the very first time.  They are now 37 weeks old and were certainly 30 weeks before we could rely on half of them laying each day.  I have no idea why they were so slow in getting going.  We bought them as a replacement for the middleaged and older ones to ensure continuity of supply but that just has not worked out.  It is a bit of a puzzle.