WARNING: This page contains spoilers from The Girl in the Attic. Read at your own risk.
Tristan Potter is the younger sister of Harry Potter, adoptive sister to Dudley Dursley, and adoptive daughter of Petunia and Vernon Dursley.
Tristan was left behind after the attack on Godric's Hollow, and was eventually taken to an orphanage by the Muggle authorities. She was adopted by the Lycanths, a family of six, at the age of two, but after she accidentally broke a vase, Mrs. Lycanth gave her the boot. Tristan wandered for a year, until she collapsed directly in the middle of the street in Privet Drive. Vernon, on his way home from work, almost ran over her with his car. Petunia gave her something to eat, and Tristan was taken in. She was given the attic for a bedroom, since every other potential spot was taken. Tristan made herself a bed from Petunia's old yoga mat, an old blanket, and a thick sheet she folded up for her pillow. She slept there for years, and soon was used to calling the Dursleys her family. At the age of ten, she accidentally attracted the attention of Harry Potter. She often woke up very early in the morning, and Harry heard the racket she caused when she tripped down the stairs. Tristan was on a search for her actual parents, which Harry aided her in. She eventually found her parents were Lily and James Potter, much to the shock of both she and Harry. Tristan was later kicked from the house by Vernon, who said that he wouldn't have another descendant of Lily and James in his home. She was found by Dudley on his walk home from school, and she walked home with him. She was excited when Harry found he was a wizard. Tristan heard the story of the Sorcerer's Stone, and she was amazed. Harry said that she would go to Hogwarts, too, since she was magical. She was with Harry and the Weasleys at Diagon Alley, but got lost after she bought her wand. Harry found Tristan and returned her to the group.
Tristan: "My God, that McGonagall lady hates me!"
Harry: "Better not let her hear you call her that, Tris."
- Tristan proclaiming Minerva McGonagall's supposed hatred of her.
Tristan had an okay year. She almost fell in the lake on the way, and was Sorted into Gryffindor. She got good grades in most of her subjects, except Transfiguration, which she barely passed. She didn't believe the rumours that Harry was Slytherin's heir, telling him that, "if you're Slytherin's heir, I'm a Cornish Pixie." Harry reminded her that she could sometimes be a bit of a Cornish Pixie at Privet Drive. TBA