I'm pretty sure they can tell if their still good. I know about 7 days in I usually catch my girls talking to their eggs so they know what their doing. Just keep an eye on her.
Yes I believe she will stay till they hatch or she is convinced they arent going to hatch. And that coop should be fine. Stuff her good with hay or straw and she'll be fine
First can we see this coop? Even a stock photo of the model online would do so we can suggest insulation. I think 40 to 50 she can keep them warm they shouldn't be very mobile yet. As long as she is with them she should be able to keep them warm enough if you pack her nest good with hay. I...