Buff Orpington hen not laying

My Buff Orpington ( Cuddles) is just into her 3rd laying season, but has only laid about 3 eggs over the past month and a half. I have flock of 4 hens and 2 of them joined us around Thanksgiving. They eat Kalmbach Hi Omega Crumbles, have a tray of oyster shells. The four birds share about a half cup of a sunflower, safflower, soldier fly larva and oatmeal blend daily. They also get some table scraps, but this is limited and not every day. They get out to free range in the lush part of my yard a couple days weekly plus limited hours on other days ( to minimize the mess in my yard). They have the full side yard of my residential lot the rest of the time, but there is no lawn. Just citrus trees, some ferns nibbled down and a couple taller trees with nothing for them to snack on.  

The buff gets picked on a bit by one of the new hens, but doesn't have any damage. Overall, the 4 girls get along.

The buff likes to be petted and attention, but also challenges me and pecks my ankles aggressively.

3 of the 4 birds have slightly poopy bottoms, but not the buff. She looks healthy.

Do you have any ideas about the lack of egg laying? One of the new hens hasn't started yet, but I don't know how old she is. She is the girl who pecks the Buff. 2 of the hens lay very well.

Any ideas or insight would be helpful. Thank you.

What latitude are you at? Maybe there isn't enough daylight yet for them to decide to start laying? What's the weather been like? Has it been snowy/frosty and cloudy?

Maybe try increasing their feed so that there's left over at the end of the day, too.

When we first got ducks, I fed them only twice a day the amount they could eat during that time. They weren't laying. Then I gave them food to access all through the day (only removing it at night), and tried to give them the amount they could eat in a day, plus a little more. They became much better layers after that.

Having said that, though, my ducks (and some of my chickens) are quite old (most more than 3 years old at this point), and they didn't lay for about 6 months. Now that it's spring, they're all mostly laying (the oldest hen, who's probably 9+ years old at this point, has maybe only laid a few eggs). Expect older birds to just not lay nearly as much as younger ones, and to not lay for many months. When did your hens slow down their laying?