Sunset Shimmer

A request from A few thing come to mind that kind of bug me with her story... one I remember during one of his live steams say something like "What if Celestia had another student" other than my mind being blown, at what time did that happened. Plus if human Pinkie suggest that there was a Twilight and Spike existed in that universe already, where is the other Sunset of that universe? Plus did the pony Sunset have the same difficulties that Twilight did when she first enter that universe

Sunset Shimmer copyright of Hasbro