"Fran (フラン Furan) is a viera warrior and wields a bow, her default weapon. She also handles the maintenance of Balthier's airship, the Strahl. Fran, like all viera, is exceptionally susceptible to the Mist that permeates Ivalice: she is affected on three separate occasions, first when they are in the Tomb of Raithwall, then when Judge Ghis heats the Dawn Shard in his airship's engine, and another time when she is in the presence of the Sun-Cryst. Likewise, in Giruvegan she could tell when the Mist had cooled. Of all the characters, she seems to be the wisest, and, despite her youthful appearance, is far older than the rest of the cast."
Source: Wikipedia, "Characters_of_Final_Fantasy_XII", available under the CC-BY-SA License.