I truly wish light mattered. Anything! It gets so tiring. I've got two again today from the breeding pen and 3 in the coop. That's too many at once so taking care of the breeding pen ones first.Thinking back, I wonder how much effect lighting has?
The ones that never went broody were given artificial light in the winter.
The later ones (that included more broodies) had natural light plus whatever might have come from street lights, house lights, and similar sources (not enough other light to affect when they went to sleep and woke up in the morning).
It's a joke when you google, "is there a way to keep a silkie from being broody."
#1: Block off their nests?

#2: Collect their eggs. There are no eggs because they aren't laying any. They'll move over to a nest that has one or more, but we take them out a couple of times a day. They sit on horse bedding pellets or straw; they get a choice.
#3: Lock them out of the coop. Been there, done that. Can't do that as then I have hens standing there wanting in to lay an egg. Open the door for them, the broody one(s) come running to plant their butts back on a nest.
#4: Confinement. There we go, that one works!