Twilight Sparkle describes Princess Cadance in a flashback in A Canterlot Wedding Part 2 as her foalsitter. The two shared a very close bond and Twilight looked back at her as "...the greatest foalsitter in all the history of foalsitters!" The two shared a special song-and-dance, which Cadance's impostor, Queen Chrysalis, was unable to repeat, which quickly raised Twilight's suspicions. The real Cadance, who was trapped in an underground cave, was able to repeat it. She tells Twilight that she could never have forgotten "...the filly I love to sit for the most."
Twilight Sparkle tells the Cutie Mark Crusaders in The Cutie Mark Chronicles how, as a young filly in Canterlot, she always wanted to go to the Summer Sun Celebration. There, she witnessed Princess Celestia raising the sun, which inspired her to learn everything she could about magic. At first she finds it difficult to magically turn a page in her book, but she quickly achieves her goal. In a time-lapse sequence, she reads through two big piles of books, and her parents enroll her in Princess Celestia's School for Gifted Unicorns, which shares a similar name with Xavier's School for Gifted Youngsters from the X-Men comic book series. However, she has to pass an entrance exam before joining. Under the supervision of four examiner ponies, she has to use her magic to hatch a dragon's egg. Despite her best efforts, the egg does not hatch, and Twilight apologizes for wasting the examiners' time. Just then, Rainbow Dash's sonic rainboom startles her and causes her enormous magical power to manifest completely out of her control, hatching the infant Spike.
With her eyes now glowing white and a purple aura around her, Twilight fires off a flurry of spells: she makes the examiners float in the air, turns her parents into potted plants and transforms Spike into a giant dragon, with his head breaking through the roof. Princess Celestia takes quick notice of the latter while walking by outside and quickly intervenes to control Twilight's magic and return everything back to normal. Twilight apologizes, but Princess Celestia is not upset; instead, she recognizes Twilight's raw power and recommends that she learn to tame her abilities through focused study. She offered to take Twilight Sparkle as her own personal protégé at the school. Twilight excitedly accepted the offer, and at that moment, her cutie mark appeared, much to her joy.
Throughout the series, Twilight continues to study magic, and in particular she studies the "magic of friendship" under the decree of Princess Celestia, and sends her reports of her studies.
Twilight is first introduced in Canterlot, where she soon learns about the impending return of Nightmare Moon. She resides in a literal ivory tower, and boasts to Spike about being Princess Celestia's "most faithful student", which is how the princess addresses her in her letters throughout the series. She is invited to a party, but she chooses to study about Nightmare Moon's imminent return instead. She is soon sent to Ponyville by Princess Celestia under the pretense of seeing to the arrangements of the Summer Sun Celebration.
Twilight first ventures into Ponyville in the first episode, where she befriends Pinkie Pie, Applejack, Rainbow Dash, Rarity, and Fluttershy. She quickly learns of the skills of her friends: she admires Rainbow Dash's ability to clear the skies, Rarity's beautiful decoration work, and Fluttershy's bird choir's melodious music. She is less impressed with Applejack's over-abundance of hospitality, Pinkie Pie's surprise party and rapid-fire one-sided conversation, and even runs away from Rarity when she practically forces her to get a makeover.
She shares many adventures with her friends throughout the course of the series.
Fulfilling Her DestinyEdit
In "Magical Mystery Cure", Twilight is assigned to fix a special magic trick in one of Star Swirl the Bearded's Spell Books, and accidentally casts a spell that changes her friends' cutie marks. But, with a little confidence, Twilight manages to fix this problem, and finish the spell. However, by doing this, she is told by Princess Celestia that she has finally fulfilled her destiny, and she is turned into an alicorn princess.
Role in the SeriesEdit
Twilight and her friends are known allies to the Shell Lodge Squad after finding out that Lord Shen had a past situation with Princess Celestia regarding Lord Cobra. She occasionally spends time with them on different adventures wit her friends, and the Cutie Mark Crusaders. In the Chronicle Series episode Magic University set 5 years before the events of MlP Season 1 and after Twilight got her cutie mark, It will be revealed by Spike that he and Twilight attended the best magic college in Equestria where they meet Haku's brother Taiku who was one Twilight's rival due to his big knack at pranking her, being the lazy, carefree and life of the party dragon but soon become friends thanks to the two things they have in common: Thier good grades and dreams of becoming Princess Celestia's top proteges. Throught their semester they foil the evil Professer Eagle Beak's plans to become the new ruler of Equestia by defeating Celestia and corrupting the students into causing a rebellion and help their Friend Princess Alice the Centaur win the heart of her crush, Brandon. After their graduation, Taiku and Twilight went their seperate ways which lead to MLP Season 1, meeting her new friends and the louge long after.