This is my first year with chickens and this forum has been very, very helpful so far. I just wanted to get a bit of advice as we adjust to our first winter. Here in Missouri we've not been above 20 or 25 degrees in about 4 days. We have 9 hens - 5 buff orphingtons and 4 barred rock. All our birds look healthy except one. She is smaller, her feathers aren't as smooth and organized as the rest, and her comb has gone from bright red to a more white-red color. Here's a photo of her (on the left) next to another. All our birds look like the one on the right except this one. Should I be concerned? Is there anything I should do?