Dexanth wrote:If you look at Twilight in that comic, she's still a blank flank. So, it looks like Sunset leaves the picture before Twilight gets her Cutie Mark, meaning she's not Celestia's student yet.
Good spot! There's a little wiggle room to be had in that time period - we see Twilight hanging out with Cadance and Shining before Sunset gets the boot, but a period of "weeks" pass before we actually see the aforementioned booting. That's certainly a long enough period of time for Twilight to have gotten her cutie mark in, if we had a reason to believe that might be the case.
I thought I was on to a really good theory regarding Twilight's early life (as I'm working towards nailing down when she and the others got their marks), but a closer look at Canterlot Wedding Part 1 just kinda killed it. I had it in my head that the timeline went like this:
1) At some point before the events of the "Neigh Anything" comic, Twilight is foal-sat by Cadance for the first time.
2) Cadance and Shining meet up, and some of the events of "Neigh Anything" occur. We know at this point that Twilight doesn't have her cutie mark yet and is still living with her parents.
3/4) Sunset Shimmer is dismissed by Princess Celestia
3/4) Twilight Sparkle gains her cutie mark and becomes Celestia's student. Twilight then moves into a room in Canterlot Castle as a kind of boarding-student, where Cadance continues to occasionally foalsit her.
5) This ultimately leads to the start of FiM, where Twilight seems to be living on-campus at the Castle with Spike.
3 and 4 are difficult to place at the moment. Anyway, the big killer was this:

To me, that looks a lot like Twilight moving into a room in the Castle. She has a chest of her stuff, she appears to be unpacking Smarty Pants... it all made sense! Only problem? No cutie mark. If she'd had her mark there, it all would've fit.