Phoebe Quantum is the mother of Chris Quantum and the wife of Professor Crispin Quantum in the anime Superbook. She serves as a warm and grounding presence in the Quantum household, providing a caring counterbalance to her husband’s scientific preoccupations. Phoebe is an avid reader who enjoys comedy films, and she is consistently available to support her son Chris as well as the family robot Gizmo, whom she treats as another child.

Her primary motivation is the well‑being of her family. She is patient and approachable, often mediating when conflicts arise. In the story, Phoebe primarily appears in the present‑day segments, but she plays a pivotal role in the episode He Is Risen. After a heated argument with Chris, she is unexpectedly transported back in time alongside the children by Superbook, becoming the first adult character to join a biblical adventure. During that journey, she meets Mary, the mother of Jesus, and gains a deeper understanding of sacrifice and forgiveness. This experience leads to a meaningful development in her relationship with Chris, as they return home and reconcile.

Her key relationships are with her husband, Professor Quantum, whom she balances with her down‑to‑earth nature, and with Chris, whom she encourages through both everyday challenges and spiritual lessons. She also shares a fond, nurturing bond with Gizmo. Phoebe does not possess supernatural abilities; her strength lies in her emotional availability, her willingness to learn from the biblical stories, and her quiet wisdom in guiding her family. She is a supportive character whose influence quietly shapes the moral and relational growth of the main characters.