"So..." Starlight Glimmer moved her ficus to the other side of the principal's desk next to the 'Best Headmare Ever' mug full of empathy cocoa and just observed Twilight for a moment. There were twitches, and sprung up hairs, as well as that creepy smile to observe, which really did not proclaim 'The Princess of the Realm is Sane' in any kind of body language. Instead of calling for the School Counselor (which would not have helped Twilight's stress level, since Starlight Glimmer had not found a way to break the news about Trixie's new job to Twilight Sparkle yet), she let out her breath and asked, "How can the School of Friendship help you?"
"I've... got a new student for you," started Twilight before rolling right into her next question. "Do you remember when we talked a few months ago about how I had been so angry that Princess Celestia would pawn off her problems on me, and you said it was because she was testing to see if I'd be a good princess at first, and to see how good a job I'd do with ruling the kingdom later, and I laughed and laughed?
"Yeeees..." started Starlight Glimmer slowly.
"Well, I just wanted to say congratulations ahead of time and to get preening lessons from Rainbow Dash when you have a chance because here's your new student and good luck!"
There was a flash of purple, and Twilight Sparkle was gone. There was, however, a creature remaining in her place.
Starlight took a cautious sip of her cocoa, let out her breath, and made her best attempt at a smile. "Welcome to our school?"