If the breeder was accurate with the age of my little Serama pullet, she was 12 weeks old when I got her September 15th (a little over 3 weeks ago). She started laying yesterday, and laid again today! Goood girl
ETA: She may have been a bit older than 12 weeks when I got her ... I didn't get a hatch date, so the age may have been more estimate on his part.