Sunset Shimmer was with her friends at Canterlot High who are the humane six as in human Twilight, human Rainbow Dash, human Fluttershy, human Pinkie Pie, and human Rarity. But then they get a surprising visitor from Equestria. Princess Celestia and Princess Luna have come to tell Sunset that it is time to come home. Princess Twilight suggested her to come home as well as having all of these human counterparts in this human world combined to Equestria. But Sunset didn't know what to say as she tears flowed down her as memories of how she acted to Celestia had come to haunt her, but Celestia stated that she has already forgiving her and after what Princess Twilight explained to her, stated that she was very proud of her.
So, let's just say this is set somewhere between the MLP Movie and Season 8. This way all of the Equestria Girls characters would be living in Equestria alongside their pony counterparts.
And if all possible, please be my guest for a possible dialogue to match with it.