She is very weak in the One Power and has been an Aes Sedai for years.
She disappears from the White Tower after Egwene al'Vere becomes Amyrlin Seat and asks all Aes Sedai to re-swear the Three Oaths on the Oath Rod. This strongly suggests she is Black Ajah, even though her name was not on Verin's list. Egwene also thought she might possibly be Mesaana.
Another possibility is that she was taken by the Seanchan.