Mistress of Novices

From A Wheel of Time Wiki

The Aes Sedai responsible for the discipline of novices and Accepted in the White Tower . She is expected to be a hard woman although most are kind as well--although that will not save the novice a hair when she is being punished. Her tools are a switch, a strap, and tough slipper. Accepted that are sent to her often are punished more severely because they are expected to know their place and the rules.

Even Aes Sedai can be sent to her for a penance.