Marlene is a woman of average height and build, and has shoulder-length blonde hair with bright eyes. When not wearing the Scout Regiment's typical uniform, her attire consists of a white button-up shirt, dark pants, and an overcoat.
Not much is known about her personality, but she is shown to be a somewhat cheerful person, as evidenced by her taunting Hange Zoë after a meeting.
Marlene is seen attending a meeting with Erwin Smith and the rest of the Scout Regiment's officers to discuss the recent revelations about Eren Jaeger's father Grisha. As the officers leave the meeting, she teases Hange about her past infatuation with Keith Sadies.
Later on, Marlene is seen with her fellow leaders watching as the scouts fight each other over the meat that is being served in celebration for their next mission.
- Hange Zoë - Marlene and Hange have a close relationship with each other, and are seemingly old acquaintances. She seems to take pleasure from teasing Hange and giving her a hard time.