In the Season 3 finale of House of the Dragon, Helaena Targaryen dies by suicide, jumping from her chamber window. Rhaenyra discovers Helaena's tapestry depicting her own death and a vision of Rhaenyra's demise on the Iron Throne, hinting at her fate.
House of the Dragon Season 3 Finale: Helaena Dies, Rhaenyra Sees Fate
Source: News18