Amy was probably born in Europe along with her little brother. She was probably a US citizen, owing to her mother's nationality. At some point in her early childhood, she lived in Romania with her mother Clara Callen and brother.
The day Clara was killed, Amy was on the beach with her brother, Callen, and her mother because Clara intended to return to the US with Henrietta Lange, her contact in the CIA. It is unclear whether Amy witnessed her mother's death at the hands of a Comescu assassin. The scene is shown from G's point of view, and the assassin's accomplice distracted young G. with a toy. Clara's death and later attempts on G's life were the result of a vendetta of the Comescu family against Callen's grandfather George Callen. George killed a Comescu family member, and the Comescus swore vengeance would include ending the Callen family line descending from George.
Later Amy and her brother were separated when they arrived in the US and placed in the foster care system, where she met and befriended Hannah Lawson (who later took her name).
Amy died of drowning while she and Hannah were playing in the park and was buried in a cemetery under Hannah's name. After hearing the story of Amy's foster care experience and death from Hannah, Callen visited his sister's gravesite. Her tombstone shows a date of death: August 25, 1978.
- Amy Callen was portrayed by actor Chris O'Donnell's real-life daughter Lily O'Donnell. Her younger brother Charlie O'Donnell portrayed a younger version of their father's character in flashbacks in the second season-finale and third season premiere.
- Amy's birth name probably included the patronymic Aleksandrova and the same surname as her brother's--Nikolaev(a).