Unless stated otherwise, all information herein is taken from A Memory of Light, Chapter 19.
Nata is a Seanchan woman who is assigned to Mat as his personal tailor. She is one of the few Seanchan women who will look directly at him. As part of dressing him, she tries to persuade him to give up his hat, but fails.
The name is apparently taken from one of the readers of the series, who is also a member of TarValon.Net