Wendy Earhart

A half-Indian, half-English girl. She joins the Special Operations Division young (aged 19), and soon becomes Joker's personal secretary. She still has the subfix in training after her work title. She is earnest, devoted, and hopelessly clumsy.

In the OVA, she is found to be more of a misplaced school-girl than an actual employee under the British Library.

In the TV series, she now serves as Joker's right-hand woman.
(Source: Wikipedia, edited)