Celestia for a 1000 years has been working day and night to bring either one into the sky, literally, but no amount of godlyness is going to stop the simplest of ailments from befalling her, goodly enough its not all that bad... just that she's not 'allowed' to touch another celestial body for awhile, and that means the long reigning monarch has to lie down and let somepony else get saddled with her job. As helpless the princess feels, its not all that bad being on vacation...