Why doesn't Twilight attend any of her classes?

[Denim&Venöm 18,982]

I'm kinda glad they didn't go into this during the movie. The new kid who has no clue of the classroom surroundings, or is dragged by the main character into school has been done a ridiculous number of times in movies, TV shows and cartoons. Refreshing that they went a different route with this, rather than add more unnecessary cliches. 

[True Rarity 1,240]

You'd think she'd understand when she realized that it was a school that she was supposed to be in class. Maybe the day she came was the last day before Thanksgiving Break.

 

I think it's really just that because Twilight never officially registered in the school, the others passed her off as someone who came to write a report on it or something.

[derpykitten 24]

Well you could say the same thing for Sunset Shimmer. She had no reason to be allowed in either, but that's when you have to dispend disbelief. You sorta have two choices: 1. don't worry about those details and press forward or 2. totally rewrite the movie.

 my question is where does sunset shimmer go when school gets out? and where was her original double? 

may be its the same case as twi (twin living in the city)

[Ponies n Pizza 38]

I think they probably did it to save time and not show it but it would have been cute to see twilight raising her hand to every question (hermione style)!