Hello all - new to chickens here. This is my first flock - 2 Australorps and 2 Buff Orpingtons - 5 weeks old. One of the Orps started sneezing 2 days ago. Immediately after her sneeze her peeps sounded slightly ... congested? Like she had a slight case of the sniffles. However - she has no visible discharge from her nostrils, her eyes are bright, and she's acting like normal. Eating, drinking, hogging all the food like usual, bossy as ever. Just the occasional sneeze. Since I'm new to chickens - I'm not sure how worried I should be. Should I wait a few days and see? Should I separate her from the rest of the birds? Is it too late and now they'll all die of some horrible respiratory disease? Other info that may be important. They are currently in a very clean brooder - aspen/pine shavings, chicken nipple waterers, organic feed, thermal panel (not lightbulb). They take day drips outside in a chicken tractor to forage and get some fresh air. I was going to move them to the chicken coop, but now I am not sure - because our nights are now getting to 60 degrees (I live in MN), and if she has a cold - would that be wise? They are mostly feathered out except for their fuzzy downy heads which have feathers starting to come out everywhere - they're definitely in their "ugly duckling" phase. Any advice would be welcome.