Do you have parental permission to expand your flock? Do you have the room to do so without crowding them? Recommendation for space for a large fowl is 4 sq. ft. in the coop and 10 sq. ft. in the run per bird. Silkies are smaller, so you could get away with 3 s.f. in coop, and perhaps 8 s.f. in run if you have a rooster, and intend to have chicks. If you crowd your birds, and your hens don't have room to safely get away from your rooster, you are going to have a coop full of terrorized hens, perhaps some bloody hens.
And, do you have a plan for any chicks you produce? The cockerels (male chicks) will fight with each other, and they will form hoodlum fluffy gangs who will run around terrorizing the pullets (females less than a year old) and ganging up on them. Can you be comfortable with culling any chicks that are hatched with birth defects or failure to thrive? Silkies are prone to neurologic birth defects b/c of their vaulted skull. You will need to familiarize yourself with how to choose good breeders to prevent these issues.