Vivian Spencer captains the equestrian club at Saint Patrick Academy, distinguished by waist-length purple hair and brown eyes. Revered as horseback riding's "queen," her exceptional horsemanship garners widespread admiration. She relentlessly pursues the prestigious Lady Crest, emblematic of sophistication and achievement.

Originally bonded with her horse Andrews, Vivian later transitions to Elizabeth. Her dynamic with Lynn Russell begins as fierce rivalry and hostility, fueled by Lynn's successful taming of Andrews—an act Vivian perceived as diminishing her uniqueness and threatening her status. Vivian's resentment intensifies when she notices Edward Philip Brighton's romantic interest in Lynn, as Vivian herself harbors feelings for Edward.

This prompts Vivian to ally with Mary Waverly, who resents Lynn for disrupting her mother's marital plans and social standing. During this period, Vivian enforces harsh treatment toward Lynn, frequently aided by her companions Phyllis and Matilda.

An unspecified accident catalyzes a significant shift: Vivian's hostility toward Lynn gradually transforms into acceptance, culminating in supportive gestures during Lynn's challenges. Vivian's cousin, Catherine Baker, regards Lynn as a commendable rival and friend—a perspective contrasting Vivian's initial stance but potentially influencing her evolution. Philip Anderson, captain of the boys' equestrian club, holds unacknowledged feelings for Vivian, obscured by her preoccupation with Edward.