Sorry to hear about this I wasn't able to load the Video my computers to slow. Also sorry to say that I don't think the silkies are a very hardy breed more than half of outs died last winter... Could just be a disease. My one chicken for the first year I got her she threw up all the time... She's fine now... Make sure your coop is nice and warm
I'm so sorry to hear that... Don't give up though. Try hatching them a bit earlier in the spring so they are older when the cold comes... The lavenders are also weak birds untill they hit a year... My lavender is down with pneumonia right now don't know how long she will last... So next time ill hatch sooner... So sorry for your loss.