I really don't think it was the cold. I mean, it went down to -2 last night and I have 4 - 8 week old silkies that had no heat lamp at all. They all made it through the night with no issues what-so-ever. She could have just had other issues..? I know my silkies are extremely hardy and very healthy.
I think hardiness may be relative to the environment in which silkies are raised in. Meaning, if 8 week old babies have been outside and gradually gotten used to the diminishing temperatures, they may be fine without a heat lamp. But, if someone has been keeping 8 week olds inside and wants to move them out into a coop...they may need a heat source. I also believe that wind, wind chill factor and dampness all make a difference. I now use AccuWeather which calculates a RealFeel temp based on a variety of factors. The app works well in the summer also, when humidity plays a role.
Hens go broody when you don’t want them to… and won’t go broody when you do.
one of my silkie chicks (approx 12 weeks) is dealing with coccidiosis. one of them had it about a month ago, I treated them but one kept having a bit of blood. I thought maybe it was just still clearing up. well, it didn't get better and now it is worse again and he/she is all hunched over 
