A short article about Pae White in the alumni magazine of the college she graduated from, Scripps College, gives her name as
Cynthia "Pae" White. The use of quotes around Pae probably indicates that it is a nickname or professional name which is not on her birth certificate, but it doesn't say how she chose it.
http://www.scrippscollege.edu/alumnae/distinguished-pae-white.php
Information online about Pae White's graphic design company gives her name as "
Cynthia A. White", with "Pae White" as a "business name":
http://www.buzzfile.com/business/Pae-White-323-222-1936/