Rainbow Dash has always had a large secret that she kept hidden away from everyone. However, this secret was revealed after Rainbow Dash received a letter from her earth pony fashionista aunt that happens to have the same name she does, stating that she is visiting Ponyville. From there, secrets and other pleasant surprises are shown at the most fabulous place in Ponyville: Carousel Boutique.
NOTE: In case if anyone wonders, Aunt Rainbow Dash borrows many characteristics from g3 Rainbow Dash along with some notable differences. Vector art was made by Tzolkine from DeviantArt