My Silkies do great with our 4 big girls. I have 2 Silkies. We even added them to the flock later. The big girls were around 5 months old and the Silkies about 8 weeks old when we moved the silkies into an area that was parallel to the big girls area. It shared a common fence, so they could check each other out and get used to each other. We left them like this for about a week, maybe more I don't remember. We would let them all out into the yard at the same time. The big girls didn't act like they cared when there was such good grass to nibble.
Then we moved them into the big girls area. We moved their whole little coop my husband built into the area so they would have their own space in case they were picked on. Which they were a little at first. Nothing major, I think just normal establishing of the pecking order. Then once the Silkies were full grown we took their little house out. They had some trouble with the ramp to the big coop though. Their little coop didn't have one. We would find them huddled just outside the coop and we would place them inside each night. Eventually they got it. Thank goodness!
Now they all get along great! No problems.
Good luck!