Dyana does not appear in the “House of the Dragon” series. She is not a character from the “A Song of Ice and Fire” novels by George R.R. Martin, nor is she part of the show’s adaptation.
“House of the Dragon” is a prequel to the popular HBO series “Game of Thrones,” and it focuses on the history of House Targaryen, a family known for their dragons and distinctive silver hair, set about 200 years before the events of “Game of Thrones.” The show is based on George R.R. Martin’s book “Fire & Blood,” which chronicles the rise and fall of the Targaryen dynasty.
Since Dyana is not a character in the series or the books it is based on, there is no specific event or storyline associated with her in the context of “House of the Dragon.” The series introduces several new characters unique to the show’s narrative, and it’s possible that new characters could be introduced in future seasons. However, as of my knowledge cutoff in 2023, Dyana is not part of the story, and therefore, there is no information about what happened to her within the “House of the Dragon” universe.