Sue Silvergray is a young female squirrel, consistently identified by a distinctive flower in her hair. She lives within a community of wild squirrels in the forest. Her grandfather is the oldest and wisest squirrel in their group, holding authority over community decisions and ceremonies.

She feels immediate attraction upon meeting Banner, a squirrel orphaned in infancy and raised by a domestic cat, drawn by his perceived innocence and sincerity which contrasts with typical squirrel behavior. Sue takes a pivotal role in integrating Banner into squirrel society, actively instructing him in essential survival skills absent from his feline upbringing, including nut gathering, safe food storage, and proficient tree navigation.

Her relationship with Banner develops romantically. This attracts the rivalry of Akācho, a cunning, arrogant squirrel suitor who employs underhanded tactics to win her affection. Despite Akācho's efforts, Sue's bond with Banner strengthens, culminating in their marriage. Their union is formally acknowledged by the community, celebrated at the series' conclusion, and results in the birth of their offspring.

Sue is generally compassionate and supportive, especially towards Banner and younger squirrels like Clay. However, she also exhibits moments of conformity to group behavior, such as participating in communal laughter directed at another character humiliated after failing to confront a predator – an action later rectified by Banner's intervention. Her presence involves themes of acceptance, community belonging, and bridging disparate backgrounds through patience and understanding.