It would certainly make for a very good episode. We already have a good setup with the end of 'Magic Duel.'



Trixie can return to Ponyville, tell Twilight 'the truth,' say she's undergone intense training, and then ask her for help on some task that will help her prove herself.



Not only would this be great for Trixie's character, it would be great for Twilight's as well, as it'd give her some insight on what it was like for Celestia to teach her magic, among other things.