I see you are in Iceland, thanks for that information, it helps. Also your chicks are only two months old, more good information.
The basic answer to when can you expect to see eggs is when you see one. I know, not much help. I’ve had some pullets start to lay at 16 weeks, I’ve had some not start until after nine months. You just don’t know. Some of it depends on the individual with heredity having an influence. But I’ve had full sisters hatched together not start laying anywhere close together. Heredity has an influence but is no guarantee.
The time of year in Iceland is against you. Daylight has a big influence on when chickens lay. Length of daylight is part of it and you are getting ready for some pretty short days. Also whether the days are getting longer or shorter has an influence. Your days, like mine, are getting shorter, that doesn’t help. Severe weather, cold or hot, can have an influence too. Chicks hatched in spring will often start to lay in late summer, early fall. That’s your best bet to get a pullet starting to lay early. So, yes, many things against you.
With all that said, I’ve had pullets start laying in the middle of December, among the shortest days of the year and still getting shorter and I do not add supplemental lights. By all the rules they should never have started laying then but they did. With their age and your climate (probably not as severe as many of us imagine) December is possible but February or March is probably more realistic for the first eggs.
Do you have an incubator? It is extremely unlikely either of those pullets will go broody anytime soon after they start laying. I have hatched pullet eggs and had some success, but my hatch rate and survivability of the chicks is lower than if you wait until the pullets have been laying a month or more. I’ve hatched them and will again, but my expectations for them are not real high.
For different reasons I don’t think your dream of hatching eggs from that cockerel and those two pullets is very realistic unless you can keep that cockerel. I know there is a strong urge to hatch your own eggs but I think your best way to increase your flock is to either get more baby chicks or get fertile eggs from someone else to hatch.
