Thank you for the idea. They don't sell fertile eggs, unfortunately, but the quails seem to be doing well.
That's reassuring. It seems like this year we will have a warm winter so she should be ok.
I just candled a couple of her eggs, and I saw veins and a heartbeat in one! I'm surprised I could see it in a quail egg. The others were darker than they were when I placed them under her, but I couldn't see anything more than that. I'm just glad they are alive. She's currently sitting on 7 quail eggs, 3 from the fridge (apparently people have had success hatching refrigerated eggs) and 4 that were fresh. She leaves her nest for about 10-20 minutes each day, but never finds her nest on her own. Before she would go to her old nest, then her old coop (she never had a nest there, but I guess she remembered it was "in her home", it was just the wrong home), and today we had to call her over to the coop when she started searching for her nest. Hopefully she soon learns where to go because I won't always be here to bring her back. She starts making a strange sound when she wants to go back to the nest.