"Lies My Sister Told Me" (a.k.a., "My Stolen Life") is a gripping mystery about twins whose lives have been filled with tragedy.
One of the great scenes in the history of the cinema is the moment in "Chinatown" when Faye Dunaway's character reveals the hidden truth about the relationship she has with her daughter in the memorable line, "You're my daughter, my sister; my daughter, my sister; my daughter AND my sister!" A similar experience occurs in the climactic moment of this film that could be paraphrased as "You're my daughter, my niece; my daughter, my niece; my daughter AND my niece!"
Jennifer has placed her sister Tracy in a mental institution after a severe mental breakdown following the deaths of her father and her husband. But years pass and Tracy has not recovered sufficiently to be released. During one of Jennifer's monthly visits, Tracy knocks her out with a hypodermic injection, switches clothes, then makes her exit from the hospital.
When Tracy "impersonates" her sister, who has become a famous writer, things go well at first. But there is a fascinating ebb-and-flow in which, after charming her way through a book signing and flirting with her publisher, Tracy begins to revert to her unstable self. By contrast, in the asylum, Jennifer cannot convince the medical staff that she her sister has succeeded in switching their identities, and she would appear to be as unstable as her sister.
The most fascinating moment of the film is the denouement in which one of the twins is back in the mental asylum. But through a clever choice in costuming, the filmmakers make it ambiguous which one of the sisters is institutionalized and which one is walking free. The poor daughter Layla has to be confused about the two women and must be thinking to her self, "My mother, my aunt; my mother, my aunt; my mother AND my aunt!"