Tanya

ターニャ

In the Manga
She appears once in the manga during a special chapter that takes place after the main story's events. A single panel depicts her serving Sven and his companions as a waitress.
In the Anime
Tanya is a waitress whom Sven had met previously. Through sheer coincidence, Tanya frequently changes jobs and relocates to different cities at roughly the same time Train, Sven, and Eve arrive in those same locations. She serves as a steady source of free food for Train and the group, allowing Sven to charge most meals "on his tab" and providing Train with bread crusts (occasionally deep-fried). She typically refers to Eve as Sven's daughter.