As a whole Marbet's personality is a naturally calm and kind person. She is also very strong-willed, willing to do what it takes to do what she thinks is right no matter how hopeless it seems, and can work through the pain of injuries. While not horribly temperamental per se, Marbet can be very opinionated. Though she likes him, Marbet initially feels envious of Uso when he is repeatedly sent on sorties by the League Militaire, despite herself being the designated pilot. These feelings recede however as the series goes on and she learns to respect Uso's abilities. Similarly she initially feels disgust towards Shrike Team leader Oliver Inoe describing him as being "like a pimp", but later it is revealed that she was in fact jealous as she marries him and becomes pregnant with their child.

Marbet's story in Mobile Suit Victory Gundam begins with her piloting the titular LM312V04 Victory Gundam's Core Fighter. She is being chased by a Zolo and a Shokew from the Zanscare Empire's BESPA force, Yellow Jacket Team. Her Core Fighter is damaged by the Zolo's attack, but she manages to damage both of her pursuers and allow Uso Ewin to subdue the Shokew in a brawl with Chronicle Asher.