Twilight Sparkle

In the past, she was Princess Celestia's personal student and later her successor. She is also the adoptive sister and best friend of Spike and is the youngest child and only daughter of Night Light and Twilight Velvet. She used to live in a library but now she is the ruler of the Castle of Friendship. She is Night Light and Twilight Velvet's daughter, Shining Armor's younger sister, Spike's adoptive older sister, Cadence's sister-in-law, and Flurry Heart's paternal aunt.