Chickgma....the other 4 might be roosters.

Or they ALL might be laying , just not every chicken every day. (That's my bantams. I have 5 and I get 3 eggs a day....but never the same 3...yes, eggs do look different and once a hen gets in the swing of laying her eggs will almost always look the same every time she lays one)
To both of you. Do you suppliment the light in their coop? If a hen doesn't have 12+ hours of light a day they won't lay. (Unless they are a couple of my chickens, who think 8 hours a day is enough most of the time, but I give them 12 hours anyway)
There are reports of some breeds of chickens not laying for 9 months....with winter setting in it might be spring before you get an egg from some of your birds. You didn't specify the breed of chickens either of you have, but the breed does make a difference. There are reports of Ameruacana hens not laying a single egg for their entire first year. On the other side, other people have had Feburary hatched chicks lay at 16 weeks. (again, breed matters) 16 weeks is still 4 months old...the average age of first egg is 20-22 weeks, which is over 5 months old.
Above all, remember Chickens are not vending machines. Even in optimum conditions they are not going to lay just because you want them to. They will lay when they lay. And the ones that don't meet your production requirements are tasty in stew or soup.