Question: Nowhere Boy is based on a biography partially written by which half-sister of John Lennon?
Context: Lennon Legend: The Very Best of John Lennon is the third official compilation album of John Lennon's solo career, coming after 1975's "Shaved Fish" and 1982's "The John Lennon Collection".  Because neither collection spanned Lennon's releases up to and including 1984's "Milk and Honey", "Lennon Legend: The Very Best of John Lennon" – considered the definitive Lennon retrospective – was compiled to rectify the situation.  It was released in the UK in 1997 through Parlophone and early 1998 in the US by EMI Records. "I'm Losing You" is a song written by John Lennon and released on his 1980 album "Double Fantasy".  It was completed in Bermuda in June 1980, after Lennon failed at an attempted telephone call to Yoko Ono.  The song is also available on the 1982 compilation "The John Lennon Collection", the 1998 boxset "John Lennon Anthology", the one disc compilation "Wonsaponatime", the 2005 two disc compilation "" and in 2010 for the "Gimme Some Truth" album.  The song was also featured in the 2005 musical "Lennon". Nowhere Boy is a 2009 British biographical musical drama film about John Lennon's adolescence, his relationships with his aunt Mimi Smith and his mother Julia Lennon, the creation of his first band, the Quarrymen, and its evolution into the Beatles.  The film is based on a biography written by Lennon's half-sister Julia Baird.  The film received its US release on 8 October 2010, coinciding with that weekend's celebrations of the 70th anniversary of Lennon's birth (9 October 1940). "Life Begins at 40" is a song by John Lennon.  It was written in 1980, the year that both Lennon and Ringo Starr turned 40 years of age.  Lennon recorded a demo of the song at his home, but it was not recorded at any of the sessions for his comeback album, "Double Fantasy."  Instead, he intended to give the song to Starr to record on his own forthcoming album, "Can't Fight Lightning."  The song's amiable country feel was well suited to Starr's singing style.  After Lennon's murder in December 1980, those plans were shelved.  However, Lennon's demo was eventually issued in 1998 on the "John Lennon Anthology" box set. "Hold On" is a song from the album "John Lennon/Plastic Ono Band" by John Lennon.  It features only vocals, tremolo guitar, drums, and bass guitar, typical of the sparse arrangements Lennon favoured at the time.  On the 2000 reissue of "John Lennon/Plastic Ono Band", "Hold On" features a slightly longer introduction.  The original version was restored on the 2010 reissue. Nowhere Man: The Final Days of John Lennon, first published in 2000 and written by New York journalist Robert Rosen, who in 1981 had access to John Lennon's diaries, is a controversial account of the ex-Beatle's last five years.  The book disputes the official view of Lennon as a contented househusband raising his son Sean and baking bread while Yoko ran the family business.  Instead, "Nowhere Man" portrays Lennon's daily life at the Dakota as that of a "tormented superstar, a prisoner of his fame, locked in his bedroom raving about Jesus Christ, while a retinue of servants tended to his every need." Thomas Brodie-Sangster (born 16 May 1990), also credited as Thomas Sangster, is an English actor and musician, known for his roles as Jojen Reed in "Game of Thrones", his voice as Ferb Fletcher in "Phineas and Ferb", as John Tracy in the ITV series "Thunderbirds Are Go", as well as his roles as Sam in Richard Curtis' "Love Actually" and Newt in the "Maze Runner" film series.  Sangster also grew in popularity for starring in critically acclaimed cult films such as "Death of a Superhero", "Bright Star" and as Paul McCartney in "Nowhere Boy".  He also had a cameo in the 2015 film "". Samantha Louise Taylor-Johnson (née Taylor-Wood, born 4 March 1967) is an English filmmaker and photographer.  Her directorial feature film debut came in 2009 with "Nowhere Boy", a film based on the childhood experiences of the Beatles songwriter and singer John Lennon.  She is one of a group of artists known as the Young British Artists. John Lennon Museum (ジョン・レノン・ミュージアム , Jon Renon Myūjiamu ) was a museum located inside the Saitama Super Arena in Chūō-ku, Saitama, Saitama Prefecture, Japan.  It was established to preserve knowledge of John Lennon's life and musical career.  It displayed Lennon's widow Yoko Ono's collection of his memorabilia as well as other displays.  The museum opened on October 9, 2000, the 60th anniversary of Lennon’s birth, and closed on September 30, 2010, when its exhibit contract with Yoko Ono expired.  A tour of the museum began with a welcoming message and short film narrated by Yoko Ono (in Japanese with English headphones available), and ended at an avant-garde styled "reflection room" full of chairs facing a slide show of moving words and images.  After this room there was a gift shop with John Lennon memorabilia available. Julia Baird (née Dykins) (born 5 March 1947) is the younger half-sister of English musician John Lennon and is the eldest daughter of John 'Bobby' Albert Dykins (1918 – December 1965) and Julia Lennon (12 March 1914 – 15 July 1958).  She also has an older half-sister, Ingrid Pedersen.  Her younger sister is Jacqueline 'Jackie' Dykins (born 26 October 1949).
Answer: Julia Baird