Regina, maternal grandmother to Saga Bergman and mother of the late Ingrid Bergman, assumed guardianship of Saga in Muhlenberg, Germany, after Ingrid's fatal bicycle accident three years before the main series. She fosters a deeply nurturing bond with her granddaughter, offering unwavering emotional support and hands-on care, including preparing meals like Saga's cherished stew. Proficient in domestic skills such as cooking and household management, Regina remains oblivious to season fairies. This inability fuels her concern over Saga's increasingly odd conduct, which she interprets as lingering grief or stress from Ingrid's death. She consistently urges open communication and provides gentle guidance during hardships.

Regina sustains a close friendship with her best friend Miranda, periodically minding Miranda's daughter Kanon, occasionally with Saga's assistance, reflecting her broader community support. In an OVA special set four years post-series when Saga is fifteen, Regina uncovers an old attic dress. This sparks Saga's recollection of her elementary school role in "Princess and the Fairy," with Regina featuring in the memory. The OVA reveals no new facets or shifts in Regina's character beyond her established caregiving.

Across all appearances, Regina endures as a bedrock of stability and affection in Saga's life, anchoring their familial connection and shared history of Ingrid's loss. Her personal narrative centers on adapting to solo parenting while upholding household rhythms and friendships, without evolving or expanding beyond these parameters.