Some just take longer than other. I’m sill waiting in an egg from one of my gals....9 months old. Unfortunately not much to be done. Sorry. It is frustrating when all others have been laying and you just waiting on that one.
Do they free range? I had one years ago I thought wasn’t laying till I found a pile of eggs under a cover under the shed. Apparently she liked it there instead of the nesting box. So maybe a possibility too?
My female Pekin is 6 (and so) months! She’s not laying either, a lot of people said it’s just too cold for her and she’s taking time. People suggested to me to up her calcium intake, but I didn’t because she doesn’t seem to be in any discomfort. Since she’s otherwise healthy, I decided to just let her decide when to lay! She’s still just as healthy and bossy as ever! Hope this somewhat relieved you! I hope our ducks are just taking time and nothing is wrong!
I had a late bloomer to(not really a late bloomer..she started laying at her time). Yours might start in the spring cuz it is getting cold. Most ducks lay all through winter, but some stop and only lay several. Most new layers and ones that should have started laying already will start in the spring and then go into next years winter being more "experienced"!