So either twin of Harry or Fem!harry/Artemis she is the master of death and immortal she can make people immortal with a potion using her blood but they must have a positive bond with her so it doesn't work with someone forcefully taking it (Voldemort). Hogwarts doesn't do the tournament till 7th year? She was born in the Potter verse when she belongs in Planetos. She has dreams of Planetos, her soulmate and meant to be family or twin(Jon Snow) depending on time line they also have dreams of her and her life. If going the twin route then she takes Harry's punishments and around 10/11 on their birthday her body gives that night and she meets fem!death/Morticia then and is given gifts (dragon eggs and a dire wolf pup familiar) and she learns about how she is in the wrong world and can go to the right world but she doesn't cause she doesn't want to leave Harry or the Fem!harry route the same as above but instead doesn't leave cause of papa Sirius, then visits Gringotts she/they has/have enough of the wizarding world by 4th year and decides to leave to Planetos. Sirius and possibly Remus left for there at end of 3rd year to establish/make a name for themselves(can't remember the name but comes from a fic of a Fem!harry x Jon Snow paring w/adopted brothers Neville and Draco). They arrive in the north beyond the wall meet the starks. Artemis wants to travel and ends up meeting her soulmate she helps them until she and everyone she has a positive tie to ends up summoned(includes the animals) cue bewildered everyone when some one asks about Planetos Morticia appears/steps up and explains that since they are the children of that world? time has stopped or slowed you can go from there. If you start at house of the dragons I would be interested if you go into ASOIAF they could be like a recluse kingdom by that time.