Guesses/Theories about the plot

Since HRY keeps saving mortals, I guess BJS seals her powers forcefully to prevent the heavenly emissaries from finding out. Only she's already pregnant and weak, and this makes her even weaker. He's not aware that she's pregnant, but she feels betrayed and leaves him. Somehow the kid dies and now she hates him to death, because if he hadn't sealed her powers, the kid wouldn't have died.