Looking for the name of a movie that I watched in the late 80's- late 90's.it was about this woman that returned claiming to be a long lost daughter named caroline and she had a step brother and a mentally challenged step sister with an over protective mother.but twords the end of the movie you find out she was an imposter that was a nurse to the long lost girls grandmother who coachs her in how to convice her family that she's caroline.

Caroline? (http://www.imdb.com/title/tt0099225/)