She is slim, with quick eyes. She has a plain brown wool dress, and a cloak with surprisingly elaborate green embroidery.  She nodded for emphasis with almost every other word.
Akarrin is little stronger than Siuan (after her stilling and Healing) in the One Power, if at all. However, she is still the strongest of the sisters sent to Shadar Logoth after the taint is removed from saidin, with the exception of Therva, who is about the same strength; Akarrin is also an expert in reading residues. 
Her level of strength is described by "The Wheel of Time Companion" as 34(22) which is a quite low level in Aes Sedai hierarchy.
She is sent to where the huge amount of saidar was detected during what was then unknown but will eventually be called the Cleansing of saidin. She reports to the Rebel Hall of the Tower of an enormous hole with huge amounts of saidin residues.  This news is the impetus for the alliance of the White Tower and the Black Tower.