My Pekin Bantams religiously hatch 1-2 days earlier than regular chickens, I always remember the first time it happened (which was with my first lot of eggs) I went in to get ready for lockdown and to remove the turning tray and rails from my incubator and there it was one starting to hatch and within 5 hours they were all hatching however the first one was still trying to hatch after all of the others were out and it seemed to have stopped trying so I gave her a hand "which I never do its a big no no" but I helped her and she was fine so I was very lucky but as I said in my experience Pekin Bantams always hatch 1 - 2 days earlier so I now prepare and lockdown earlier as for silkies Im not sure I have never had them, Good Luck with all of your chickens