Five years. Five years of study. Five years of practice. Five years of magic. Five years without a friend in the world. But then, it's just another five years to Twilight, the only thing separating it her mind from times prior being Nightmare Moon's attack and quick defeat at the hooves of Celestia.
Luna had been an interesting roommate since she moved into the castle and Twilight fell quickly back into her life studying under Celestia. Though all good things must come to an end, thus why the Grand Galloping Gala this year has ended in calamity. Twilight must now make the friends she never had the chance to meet and bring an end to the era of darkness and chaos that has befallen Equestria.

First story so, yah.

By the way, Shining Armor and Cadence got married quite a few years earlier here than in the show and have a child two years younger than the Crusaders.

Cover art made by InternationalTCK
His Deviantart: http://internationaltck.deviantart.com/gallery/#/d58e8y6