Amy is a twelve-year-old girl who faces heavy responsibilities placed upon her by her family. She feels burdened by the expectation to constantly supervise her developmentally disabled sister. She seeks independence and finds refuge at her great-grandparents' empty house. She is perceptive but overwhelmed by guilt regarding her home life.

Aunt Clare recently returned from Chicago to prepare her late grandparents' house for sale. She projects an image of independence that Amy admires. She strongly dislikes the dollhouse in the attic and refuses to discuss the past. She hides intense, unspoken grief regarding her grandparents.

Louann is Amy's eleven-year-old sister who has a developmental disability. She views the world in a literal, uncomplicated way and requires extra attention from her family. She attends after-school programs to build her independence. She often unintentionally creates social difficulties for Amy but remains earnest and observant.

Ellen is a new friend of Amy's who represents typical childhood experiences. She is patient and understanding. She stands by Amy even when social situations become complicated. She shares Amy's fascination with the antique dollhouse and encourages her to investigate its oddities.

Amy's mother is highly protective of her youngest daughter. She constantly supervises Louann and expects Amy to share this heavy caretaking responsibility. She worries frequently. This anxiety manifests as strictness and causes tension with her eldest daughter.

Paul is Amy's father and Aunt Clare's younger brother. He grew up living with his grandparents after his parents died. He expects Amy to face the consequences of running away but eventually agrees to let her stay temporarily with Aunt Clare.

Grandma Treloar is Amy's late great-grandmother who previously owned the house Aunt Clare is clearing out. She raised Aunt Clare and Paul after they were orphaned. Her exact fate is a sensitive subject that Aunt Clare refuses to discuss.

Grandpa Treloar is the late great-grandfather of Amy and Louann. He lived in the large house with his wife and took in his orphaned grandchildren. The details surrounding his past remain shrouded in mystery for the younger generation.

Mrs. Peck is a caregiver and instructor who works with Louann after school. She focuses on teaching Louann practical skills, such as how to ride the bus, to build her independence.

Kathy is one of Amy's friends invited to the combined birthday party. She treats Louann like any other person at the gathering. This simple act of kindness surprises Amy and makes the party a success.