Author: Leora Oldessroth
A similar entry appears in the Wheel of Time Companion confirming the information available in the main story arc.
Zheres is a man that Birgitte remembers from a past life.
Birgitte tells Nynaeve the story of Mathena and Zheres in response to Nynaeve insulting her; Birgitte implies that Nynaeve is like Mathena, looking down her nose at men until she was kissed for the first time by Zheres.
(Reference: The Fires of Heaven, Chapter 47)
"Birgitte's smile tightened. 'And I knew a woman like you, once. Mathena looked down her nose at men, too, and even had a poor fellow executed for coming on her by accident while she swam naked. She had never even been kissed, until Zheres stole one from her. You'd have thought she had discovered men for the first time. She became so besotted, Zheres had to go live on a mountain to escape her. Watch out for the first man to kiss you. One has to come along sooner or later.'" (Birgitte to Nynaeve; The Fires of Heaven, Chapter 47).