Silkies are probably the best broody chickens out there! They start early and will just keep on at it. My silkie, Princess, goes broody even during the winter (which isn't always a good thing). She will go broody in just about any place, sitting on just about anything, even a piece of corn cob.
Breaking-up a broody isn't always easy. Some break-up just by you picking them up and taking them off the nest, others will sit on an empty nest for the full 3 weeks. It is generally best to let a silkie raise her eggs, since trying to break them up is difficult and stressful, but it is important to consider what you will do with the chicks, especially if half of them are roosters.
Methods for breaking-up a broody includes locking them away from the nest, putting them in a crate without nesting material, and others. Some are more stressful on the hen and are best avoided, such as starving them.
If you decide to let her raise eggs, make sure that other chickens don't bother her or lay in her nest. You don't need to put food and water right near her, she will get up for about 5-15 minutes every day to feed, water, and use the bathroom (they sometimes skip a day or two, so no need to worry). You can put her in a pen, however, with some food and water nearby if you are afraid the other chickens will bother her. Letting her stand up and stretch and flap her wings is important, and dust bathing will help prevent mite problems, which broodies can get otherwise.
Best of luck with your chickens!
