Mercredi

Mercredi (French for Wednesday), although aged only 13, is Eclipse's Private Secretary and can be considered to be her "right-hand girl". She is extremely talented at data gathering and her abilities almost rival a computer. The job also gives her time to hang out with a lot of the ES Members and she's a friend of Éclair and Lumière. Mercredi also excels at making tea, and usually fixes a batch for Eclair and Lumiere after each of their missions. Mercredi goes missing when the GOTT towers are destroyed and is presumed dead, however she turns up again in the rebuilt GOTT building without her usual uniform. In actuality her true codename is Pfeilspitze (German, "arrowhead"), and has been working as a double agent inside the GOTT for her partner, Armbrust.

In Kiddy Girl-AND she goes under a new name: Hiver. And she has also become the leader of GTO.

(Source: Wikipedia)