Lavender Ams are mostly all affected by a gene that makes the feathers fray. It is a big drawback for showing lavenders (called self-blue in shows). I suspect you are seeing the results of that gene, as silkied seems to be completely recessive.
The mother was certainly one of the cuckoo ams in my flock. Good chance that several of them have the gene. If I look for it, I can spot the silkied chicks quite young, maybe a week of age. I might put that same pen back together next spring and hatch a lot of chicks, keeping any that are silkied, including males. The males will only be single barred, but when crossed to a silkied sister, all chicks will be silkied and half will be single barred. Or I could put them with a smooth, but cuckoo, hen and half the male offspring will be double barred and all will carry the silkied gene. The first pairing makes more sense, as the pen I really want in the end is silkied, single barred pullets and a silkied, non-barred cockerel.
I love working out the genetics in my head for future breeding.
