Avery is a student at Luna Nova Magical Academy, though little is revealed about her life before arriving at the school. It is generally assumed that she comes from a magical family, which informs her traditionalist views. Her role in the story is that of a supporting character, most often seen as part of the group of students who initially look down on the protagonist, Atsuko Kagari.

In terms of appearance, Avery is a girl of average stature with dark purple hair and thin eyes of the same color, which are framed by long eyelashes. Her hairstyle differs between the original film and the television series; in the films, her hair is neck-length with a fringe swept to the right, while in the series, it is shoulder-length with a longer fringe parted on both sides. She is consistently depicted wearing two red hairpins, one on each side of her head. For her Luna Nova uniform, her personal touches include a pale violet body belt and hatband, matching the ribbon sash on her broom.

Avery's personality presents a blend of traits. She is portrayed as a diligent student who can be demanding and harsh, particularly towards those she considers weak or ignorant about magic. She shares the mocking tendencies of her friends Hannah and Barbara, though she is generally less insulting and more able to get along with others than they are. She has a clear dislike for non-magical people, as shown when she expresses contempt for tourists who overrun the academy during holidays. A significant and distinguishing aspect of her character is her personal ambition: she loves to sing and dreams of becoming a singer-songwriter when she grows up, a goal she actively pursues by creating content as a WitchTuber.

Her motivations stem from a combination of traditionalist values and personal ambition. She seeks to uphold the prestige of magical heritage, which leads her to reject and humiliate witches who do not come from magical bloodlines, such as Akko. At the same time, she is driven by her own dream of musical fame, which gives her a personal goal outside the academy's standard curriculum.

In the story, Avery is not a main character but serves as a recurring face among the student body. She is present for major events, such as the welcoming ceremony for the Earl of Hanbridge and his son, Andrew, and participates in collective actions like giving her Fuel Spirit to support Akko and Diana in a major battle. She is most active in the early parts of the series, often alongside Hannah and Barbara, to reinforce the social hierarchy at Luna Nova that Akko struggles against.

Avery has several key relationships. She is very close with Hannah England and Barbara Parker, with whom she shares a disdain for non-magical students and a tendency to mock others. The three are frequently seen discussing their vacations and the academy's affairs together. Her primary social circle, however, consists of her roommates, Mary and Blair, with whom she is often shown eating lunch and attending gatherings. Her relationship with Akko Kagari is one of initial contempt, as she ridicules Akko for not being from a magical family. Despite this, in some additional game content, she shows a willingness to let Akko help her improve her music videos, suggesting a potential for a less hostile dynamic.

There is little notable development for Avery in the main storyline; she remains a static background character whose views are not challenged or changed in a significant way. Her role is consistent throughout the television series, serving as part of the collective of traditionalist students.

As for her abilities, Avery is a competent-enough witch to attend Luna Nova. She possesses a flying broom and is proficient in using standard spells taught at the academy, though no specific or unique magical talents are attributed to her. Her most notable abilities are arguably her musical talents and her ambition to build a career as an online performer, which set her apart from her more one-dimensionally antagonistic friends.