That will trigger pecking behavior sometimes, they get bored and confused, then they will sometimes take their frustrations out on another member, any crested or weaker birds can become the target. I shovel my run out than put down hay or bedding and I get mine back outside, otherwise people use...
I occasionally see where a chicken will get targeted because there's something wrong with them or their behavior is off, but not enough to be noticed by us humans. Unfortunately the only way to stop bullying is to remove the bully or the victim, but I find there's usually a reason it started out...
I would advise you not to keep silkies with large breeds as they often become bullied, I would set her up somewhere without bigger breeds and get her some others her size or let her hatch a family. Silkies can be killed by bigger chickens.