My three year old hen, Nugget, was mid-molt when the temperatures started dropping. During the day we have temperatures in the high 60s but at night it sometimes dips down into the 30s. Tonight I noticed she was shivering when I went to lock up the coop. Is there anything I can do to help her keep warm without interfering with her feather regrowth? I don't want her to not have enough feathers to keep her warm because I knitted her a sweater or something.