Grew up in Brooklyn Heights, just across the Brooklyn Bridge from Manhattan, except for the four years her family spent in Woodstock, New York. When Jennifer was 10, the friend suggested that her parents take her to a modeling audition. She began appearing in newspaper and magazine ads (see Seventeen magazine pictures) and soon moved on to TV commercials. A casting director saw the girl and introduced her to Sergio Leone, who was seeking a young girl to dance in his gangster epic Once Upon a Time in America (1984). First appearance on celluloid was a British TV series "Tales of the Unexpected" (1979) in 1984. Her first movie appearance was in Dario Argento's Phenomena (1985). Was "engaged" in an unconventional sense i.e. no real plans to marry, to Bill Campbell, her co-star in The Rocketeer (1991). In three of her movies - Dark City (1998), Requiem for a Dream (2000), and House of Sand and Fog (2003) - she appears standing at the end of a pier in a striking image. All three directors created the shots for different reasons, and they are not an homage or reference to each other, just an unlikely coincidence.