She had brown eyes and long black hair which was going white at the temples.
Being a Sitter in the Hall for a time means that Jarna was also a high ranking sister and a strong channeler by Aes Sedai standards.
She participated in the torture and murder of Tamra Ospenya.
Ishamael learned that she had given the order to search for and kill the Dragon Reborn, and abandoned her within a ter'angreal for which no use had been found that had not been tried in centuries. She died shrieking and screaming over a period of ten days. The use of this ter'angreal, or even how to activate it, remains unknown. Alviarin is appointed after her to take over the Black Ajah.
She was well-loved and respected by many Aes Sedai, seen as a model of virtue. All of the Tower and those who could reach Tar Valon in time attended her funeral where they buried what remained of her after her ordeal in the ter'angreal.