Marlene was a woman of average height and build, and had shoulder-length blonde hair with bright eyes. When not wearing the Scout Regiment's typical uniform, her attire consisted of a white button-up shirt, dark pants, and an overcoat.
Not much was known about her personality, but she was 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.
After the scouts successfully seal the hole in Wall Maria they are attacked by the Beast Titan and its forces. Erwin orders Marlene and Dirk's teams to meet up with Klaus's team to protect the scouts' horses. During the fighting, however, Marlene and her team are killed by the Beast Titan, which starts throwing crushed boulders at them, ripping them all to pieces.
- Hange Zoë - Marlene and Hange had a close relationship with each other, and were seemingly old acquaintances. She seemed to take pleasure from teasing Hange and giving her a hard time.