Can you post some photos of them? We might be able to give you a better idea of how close to or far away from the onset of production they are. What is their current diet?
ETA - also, are you certain they are not producing? Depending on the other breeds of birds you currently have (if you do have) you can often miss a new egg in the box if they start off without giving you those adorable tiny pullet eggs (have one bird that started off with whoppers and has kept right on trucking - only reason I knew it was here is she is my only OE in the bunch, had she laid plain brown I would have attributed it to one of my older hens). Also, if they were hatchery sourced birds it's important to consider you may be looking for a particularly dark/speckled egg from your Welsummer and miss seeing her start laying since they often don't produce what you expect due to being production bred vs. having been focus bred for egg color.
I have 4 other hens that lay everyday give or take 1 day each off. So I get 4 eggs most days 2 off white pink from my 2EE's and 1 jumbo brown and 1 regular brown. I have thought about that cuz some times I get some speckles on the 1 regular brown egg but then that would mean that hen wouldn't be laying since its everyday I get that egg.