Brigitte first appears in 0108: Illecebrouss on the arm of Julius Lymos, wandering the streets of the 5th level of Clorencia City, seeking out The Gaslight, a dance hall and cabaret. Oliver escorts the pair to the club after eliminating a nearby spybot.
It's unknown how Brigitte and Julius are acquainted. From Julius's dialog, it does not seem that they've known each other long. Many fans theorize that Brigitte is a "lady of the evening".
In the Gentleman Caller, Brigitte appears under the name Mari, masquerading as an innocent young student at Clorencia University. She attempts to convince the Player Characters to give her a book on ancient Tsuankhotal Empire technology. What this means about her current involvement in the larger Clockworks storyline is as yet unknown.