Yes, its the same one egg. At first it was kind of a joke. Another chicken had stolen and sat on 9 eggs, hatched 2. So the family figured this is just Chloe's strange way. Unless all silkie hens are a little strange. She never has been very social with the other chickens and has a few strange little obsessions, esp. with water. Very much like an autistic human child. In fact we sort of figured she's kind of autistic. So the one egg obsession, it fit her personality. Our nine year old son would go count it with her, "lets see, thats oooone....yes they're all there" it's so sweet, she stands up and rolls it gently back between her knees and says sweet little gurgles to it. But sometimes after the other chickens went out in the morning, she'd be running around cackling all upset, far away from her egg. So we'd show her the water, she'd take a drink (but only if it was in exactly the right place) and we'd show her the food, she'd eat, then make a giant poop, then turn to her nest and gently coo to her egg, count it and commence brooding again. And there's no evidence she's laid any other eggs all this time. We do coop care every morning.
So sad. If it's not viable, I dont know what's next for her. Wish I could slip a little chick under her wing.