What does Darkstalker sense about the egg that contains his sister in Chapter Two of the novel, Darkstalker?

Darkstalker senses his sister in another egg. She does not have the strong sense to hatch as he had. She is not called forth by the moons like he was. He could touch her egg and summon her. However, he can see how they would share power and their mother's love, so he decides to let his sister hatch in her own time when the moons are no longer full. Then he will be the only special one.