Question: When did Sarah Polley become known as a child actor?

full_context: Document 1: Teen idol: A teen idol is a celebrity with a large teenage fan-base. Teen idols are generally young but not necessarily teenaged. Often teen idols are actors or musicians, like Ariana Grande and Niall Horan, but some sports figures also have an appeal to teenagers. Some teen idols began their careers as child actors, like Lindsay Lohan.
Document 2: Sarah Gadon: Sarah Gadon (born April 4, 1987) is a Canadian actress. She first gained recognition with roles in David Cronenberg's "A Dangerous Method" and "Cosmopolis". She has guest starred in a number of notable television series including "Are You Afraid of the Dark?", "Dark Oracle", "Doc", "In a Heartbeat", "La Femme Nikita", "Life with Derek" and "Mutant X". She also does voice-acting, lending her voice to "Mattimeo", "My Dad the Rock Star", "Ruby Gloom", "Total Drama" and "Wayside". In 2015, she co-starred in Miramax's supernatural thriller "The 9th Life of Louis Drax" and portrayed a young Elizabeth II in the comedy "A Royal Night Out". In 2016, she starred in the Hulu adaptation of Stephen King's miniseries "11.22.63", in which she portrayed James Franco's love interest, Sadie.
Document 3: Margaret O'Brien: Margaret O'Brien (born Angela Maxine O'Brien; January 15, 1937) is an American film, radio, television, and stage actress. Beginning a prolific career as a child actress in feature films for Metro-Goldwyn-Mayer at the age of four, O'Brien became one of the most popular child stars in cinema history and was honored with a Juvenile Academy Award as the outstanding child actress of 1944. In her later career, she appeared on television, on stage, and in supporting film roles.
Document 4: Jodie Foster: Alicia Christian "Jodie" Foster (born November 19, 1962) is an American actress and filmmaker who has worked in films and on television. She has often been cited as one of the best actresses of her generation. Foster began her professional career at the age of three as a child model in 1965, and two years later moved to acting in television series, with the sitcom "Mayberry R.F.D." being her debut. In the late 1960s and early 1970s, she worked in several primetime television series and starred in children's films. Foster's breakthrough came in Martin Scorsese's "Taxi Driver" (1976), in which she played a teenage prostitute; the role garnered her a nomination for an Academy Award. Her other critically acclaimed roles as a teenager were in the musical "Bugsy Malone" (1976) and the thriller "The Little Girl Who Lives Down the Lane" (1976), and she became a popular teen idol by starring in Disney's "Freaky Friday" (1976), "Candleshoe" (1977) and "Foxes" (1980).
Document 5: Stories We Tell: Stories We Tell is a 2012 Canadian documentary film written and directed by Sarah Polley and produced by the National Film Board of Canada (NFB). The film explores her family's secrets—including one intimately related to Polley's own identity. "Stories We Tell" premiered August 29, 2012 at the 69th Venice International Film Festival, then played at the 39th Telluride Film Festival and the 37th Toronto International Film Festival. as well as the 70th greatest film since 2000 in a 2016 critics' poll by BBC.
Document 6: Child actor: The term child actor or child actress is generally applied to a child acting on stage or in motion pictures or television, but also to an adult who began his or her acting career as a child; to avoid confusion, the latter is also called a "former child actor". Closely associated is teenage actor or teen actor, an actor who reached popularity as a teenager.
Document 7: Sarah Polley: Sarah Ellen Polley {'1': ", '2': ", '3': ", '4': "} (born January 8, 1979) is a Canadian actress, writer, director and political activist. Polley first garnered attention as a child actress for her role as Sara Stanley in the Canadian television series "Road to Avonlea" (1990–1996). She has starred in many feature films, including "Exotica" (1994), "The Sweet Hereafter" (1997), "Guinevere" (1999), "Go" (1999), "The Weight of Water" (2000), "My Life Without Me" (2003), "Dawn of the Dead" (2004), "Splice" (2009), and "Mr. Nobody" (2009).
Document 8: My Life Without Me: My Life Without Me is a 2003 Canadian drama film directed by Isabel Coixet and starring Sarah Polley, Mark Ruffalo, Scott Speedman, and Leonor Watling. Based on the book "Pretending the Bed Is a Raft" by Nanci Kincaid, it tells a story of a 23-year-old woman, with a husband and two daughters, who finds out she is going to die soon. The film was produced by Pedro Almodóvar's production company, El Deseo.
Document 9: Movie star: A movie star (also known as a film star and cinema star) is an actor who is famous for their starring, or leading, roles in motion pictures. The term is used for actors who are marketable stars and whose names are used to promote movies, for example in trailers and posters.
Document 10: Ellen Page: Ellen Grace Philpotts-Page (born February 21, 1987), known professionally as Ellen Page, is a Canadian actress. Her career began with roles in Canadian television shows including "Pit Pony", "Trailer Park Boys", and "ReGenesis". Page starred in the 2005 drama "Hard Candy", for which she won the Austin Film Critics Association's Award for Best Actress. Her breakthrough role was the title character in Jason Reitman's comedy film "Juno" (2007), for which she received nominations for Academy Award, BAFTA, Golden Globe and Screen Actors Guild Award for Best Actress, and won awards including the Independent Spirit Award, MTV Movie Award and Teen Choice Award for Best Actress Comedy.
Document 11: Sarah Nicklin: Sarah Nicklin is an American stage, film and television actress. Her career is strongly focused on independent films and she is known for her girl next door quality, strong emotional range, and ability to transform into dark damaged characters. Her first notable film role was as Sister Kelley Wrath in the independent cult-hit Nun of That in 2009. Since then she has received four "best actress" nominations for her roles in Exhumed, Choices, Debeaked, and Zombie Allegiance. She has also starred in the cult hit "Atomic Brain Invasion". She also played the leading role of Sarah Burke in the horror-suspense thriller "Abandoned Dead".
Document 12: Junior idol: In Japan, a junior idol (ジュニアアイドル , junia aidoru ) , alternatively chidol (チャイドル , chaidoru ) or low teen idol (ローティーンアイドル , rōtīn aidoru ) , is primarily defined as a child or early teenager pursuing a career as a photographic model. Generally, this means gravure, or "cheesecake", fully clothed shots; but, junior idols can, and some do, eventually enter the AV industry. Child actors, musicians, and J-pop singers (whose musical genre is often termed idol pop) can also be considered junior idols and are often featured in photobooks and image DVDs.
Document 13: Breakthrough role: A breakthrough role, also known as breakout role, is a term in the film industry to describe the performance of an actor or actress in a film or television show which contributed significantly to the development of their career and beginning of critical recognition. Such a moment in an actor's career may often occur some time after they begin acting as their roles become more substantial. Often a breakthrough role is a significant increase in importance in the actor's part in the film moving up from a minor character or extra to one of the leading cast, or a "high impact" role in a film which has mainstream success and results in the widespread recognition or popularity of the actor. Martin Shingler defines a breakthrough performance as one which "attracts the attention of film critics, or receives rave reviews and is subsequently nominated for a major film award."
Document 14: List of surviving silent film actors: This article lists the known confirmed surviving silent film actors, including those with uncredited roles. The first sound film was released in 1927 and the silent film era ended in about 1929. All of the surviving silent actors were child actors.
Document 15: Away from Her: Away from Her is a 2006 Canadian drama film written and directed by Sarah Polley and starring Gordon Pinsent, Julie Christie and Olympia Dukakis. The feature-length directorial debut of Polley, the film is based on Alice Munro's short story "The Bear Came Over the Mountain", from the 2001 collection "Hateship, Friendship, Courtship, Loveship, Marriage". Executive produced by Atom Egoyan and shot in Ontario, it debuted at the 2006 Toronto International Film Festival.
ground_truth: who reached popularity as a teenager.