After the Great Battle, and Twilight’s Coronation to be queen, Celestia and Luna gave up their Alicorn magic and status. With that, they lost their flowing manes and wings, as they had just been unicorns before.
 
With the loss of their alicorn magic, they thought that they would simply wither away, resigning to their fate, but found that in fact, their bodies had simply stopped aging entirely, alicorn magic or not. After that discovery, they then went their separate ways for the first time since Nightmare Moon’s defeat.
 
Celestia left for Mount Aeris to reunite with her long lost lover, Novo of the Hippogriff, and Luna stayed behind, finding love of her own a little closer than she presumed. They, however, write to each other almost daily, and meet up at least three times a month. They’re closer than ever and are happier with the weight of ruling off their shoulders.