and Welcome To BYC! If you can increase the space they have and give them more things to do to keep them entertained that might possibly help (crowded and/or bored birds are more likely to bully and it is common in the winter when they don't go outside much). You might try putting pinless peepers on all three of the other birds if they are all picking on her to see if that slows down the bullying. If she is a white or light colored bird be sure to put Blu-Kote or something like that on her head, the color sometimes helps stop picking. But unfortunately birds like silkies often need to be kept separate from other birds because they so often do get picked on.
Hello
