Cassie is a third-year graduate student studying occupational therapy who takes a highly paid live-in nanny position to make ends meet. Burdened by the emotional scars of her neglectful childhood, she often struggles with self-doubt and a fear of being a burden to others. She formerly supplemented her income by making content on OnlyFans, an account she deleted after a painful rejection from an anonymous subscriber.

Aiden is an executive chef at a popular restaurant and a struggling single father. Since the sudden death of his daughter's mother a year prior, he has had full custody but finds his demanding career leaves him little time for parenting. He is deeply insecure about his abilities as a father and fears his daughter resents his frequent absences.

Aunt Iris is the older sister of Sophie's late mother, Rebecca, with whom she co-owned a flower shop. Having lost her sister, she views Sophie as her only remaining family and is fiercely protective of her niece. She is highly critical of Aiden's busy lifestyle and believes she would be a more suitable guardian for the child.

Sophie is an energetic nine-year-old girl struggling to cope with the sudden loss of her mother, Rebecca. She acts out to test boundaries but secretly harbors deep loneliness and fears being a burden to her father. Underneath her strong-willed exterior, she is highly perceptive of the adults around her.

Wanda is Cassie's 72-year-old eccentric neighbor and closest confidante. Having lived a full and independent life, she frequently goes on casual dates and plays bingo, embracing her freedom. She acts as a vital support system for Cassie, offering unconditional love and straightforward wisdom when Cassie's self-doubt takes over.

Rebecca was Sophie's mother and Aunt Iris's younger sister. Though she and Aiden were never in a serious relationship, they successfully co-parented Sophie for eight years. Her sudden death a year prior to the story's events leaves a massive emotional void in the lives of her sister, her daughter, and her former partner.

Camila is a fellow student in Cassie's occupational therapy graduate program. She provides Cassie with peer support and a connection to life outside the townhouse, eventually helping to organize social outings that benefit both Cassie and Sophie.

Lucia is Camila's young niece, roughly the same age as Sophie. She is introduced to Sophie during a trip to the zoo in an effort to help the grieving girl expand her social circle and make friends her own age.