I know we went over this before when she went to her 3 day break the first time so we thought maybe it was that.  Could you tell your girls were molting?   She still looks the same from what I can tell but I haven't really examined her.  but she is eating and running all over fine so assuming there is nothing "wrong" with her (like sick, egg bound etc) so just figure the lack of day light.   What is odd is the 21st was the shortest day of the year and now they are getting longer.  So leading up to the shortest day she went back to every other day, then she stopped on the shortest day and hasn't laid since.  if anything would have thought if it was that then she would have stayed at 3 days apart or went to 4 then 5 etc and gotten longer between.  not went from no eggs for 3 days between laying to laying every other day then boom stopping.......   so maybe it is a molt?     She only laid 9 so far for the month of Dec....