From Tar Valon Library
Hashala is a novice in the White Tower. She has short, bobbed black hair.
She tells Siuan and Bryne where Egwene is. Gareth considers tying her up so that she won't give them away, but after telling them she is loyal to Egwene, the true Amyrlin, they take her with them.
(Reference: The Gathering Storm, Chapter 41).