Orphan is based on a disturbing true story of a woman, Barbora Skrlová, who posed as a 13-year-old boy in Norway. A similar incident occurred years after the release of Orphan, where an Indiana couple adopted a Ukrainian girl, Natalia Grace, who exhibited troubling behavior like Skrlová.

According to the research findings, Esther's character is a psychopath. First, there are five psychopath behaviors: liar, lack of feeling guilty, lack of empathy, manipulative, and aggressive. Second, Esther becomes a psychopath due to biological and environmental factors.

As Bell said: "We had three body doubles and everything from her wardrobe had to be sized up, but also fit her adult body like a child. Anytime adults were around her the camera would be at an angle to force the perspective–tricks that have been done in Hollywood movies forever."

However, Esther is actually a 33-year-old mentally unstable Estonian woman who has a hypopituitary disorder that makes her look much younger than she actually is and who has since impersonated a little girl who died years ago at the hands of the horrid Albright family, whose matriarch in particular targeted her life.