Coop 1:
My 6 older girls (4 Showgirls, 1 Bantam Cochin and 1 RIR bantam mix) were all laying when I got them 2 years ago. They were between 4 and 6 months old at the time. Just 5 weeks ago they gave me 29 eggs in a week, but after losing my older rooster they went down to 6 eggs a week. Now they're up to 14 a week.
Coop 2:
I also have a mixed flock of 17 black Australorps (not laying yet), red Sexlinks, Amberlinks and ISA Browns (6 are laying) that are all about 18 weeks now. I'm not sure which one laid the first egg but they were 16 weeks old. That week the "youngins" as I call them, gave me 6 eggs. This week I gathered 22 eggs, up to 6 a day so far but they're only starting week 3 of laying.
Coop 3:
I had 3 14 week old pullets but lost one suddenly just 2 days after losing my adorable Silkie rooster who was 3 1/2 yrs old. Neither of the two are laying yet.
Between the ones that are laying, they gave me 36 eggs this week (12 last week).
In addition to my 25 girls, I have 6 roosters (soon to be 5 once I give one to a neighbor for his girls, they ended up with not 1 rooster from their chicks). I have 1 each in coops 1 and 3 and coop 2 has 4 roosters currently with only minor squabbles, each has their little group.
I'm also raising 6 ducks (1 drake, 5 girls unless 1 more is a drake), 2 are 18-22 weeks, 4 are 14-16 weeks. They were given to me so I can only approximate their ages based on former owner.
Photo is my first egg from my unknown girl in coop 2, it's slightly larger than a Bantam egg.