Question: Who is the mother of the performer of Off & On?

full_context: Document 1: Get Over You / Move This Mountain: "Get Over You" and "Move This Mountain" are two songs recorded by British pop singer Sophie Ellis-Bextor. In most countries, "Get Over You" was released as the sole single, but in the United Kingdom, the two tracks were released as a double A-side single on 10 June 2002. The former track was taken off the "Read My Lips" album reissue, while the latter was an album track in the original album release.
Document 2: Nicola Roberts: Roberts was born in Stamford, Lincolnshire, when her mother was 17. At the time of her birth, her father was working for the RAF and the resulting pay led to financial struggles which saw her father move to work for Ford Motor Company whilst her mother became a photographer to help the family monetary problems. Roberts grew up in Runcorn, Cheshire.
Document 3: Spectre (2015 film): The song was released as a digital download on 25 September 2015. It received mixed reviews from critics and fans, particularly in comparison to Adele's "Skyfall". The mixed reception to the song led to Shirley Bassey trending on Twitter on the day it was released. It became the first Bond theme to reach number one in the UK Singles Chart. The English band Radiohead also composed a song for the film, which went unused.
Document 4: Off & On: "Off & On" is a pop song released by British recording artist Sophie Ellis-Bextor as the fifth overall single from her fourth studio album, "Make a Scene". It was released on 11 April 2011, exclusively in the Russian Federation as a digital download, a week before the release of the album there. Ellis-Bextor appeared on various talk shows in the United Kingdom to promote the song, including "The Rob Brydon Show", despite it not being released as a single there.
Document 5: Juno Temple: Temple was born in Hammersmith, London, the daughter of producer Amanda Pirie and film director Julien Temple. Her aunt is politician Nina Temple. She grew up in Taunton, Somerset, and attended Enmore Primary School, Bedales School, and King's College, Taunton. She has two younger brothers: Leo and Felix.
Document 6: Laura Bates: Bates was born on 27 August 1986 in Oxford to a mother who taught French and a physician father, and grew up in Hackney and Taunton, and has an older sister and a younger brother. Her parents divorced when Bates was in her twenties. She read English literature at St John's College, Cambridge, and graduated from the University of Cambridge in 2007. Bates remained in Cambridge for two and a half years as a researcher for the psychologist Susan Quilliam who was working on an updated edition of The Joy of Sex.
Document 7: Mixed Up World: "Mixed Up World" is a song by British singer-songwriter Sophie Ellis-Bextor, released in 2003 as the first single from her second studio album, "Shoot from the Hip". It peaked at #7 on the UK Singles Chart. It was considered somewhat of a success. The single includes an easy-listening, chillout B-side, called "The Earth Shook the Devil's Hand". The video for the song features various dancers wearing a mix of bright and dark colours. It also features men in bowler hats as Sophie moves between giant black and white punctuation marks. It was directed by Rupert Jones. It was the first video that shows Sophie's blonde hairstyle. A short clip from the video was featured in an ad on Australia's VH1 channel in June 2006. "Mixed Up World" sold 35,000 copies in the United Kingdom.
Document 8: Samantha Bee: Bee was born in Toronto, Ontario, the daughter of Debra and Ronald Bee. She has said of her family: "Dating from well before the turn of the 20th century, if there has ever been a successful, happy marriage in my family lineage, I've yet to hear about it." Bee's parents split up soon after her birth, and she was initially raised by her grandmother, who worked as a secretary at the Catholic school Bee attended, on Roncesvalles Avenue during her childhood. She attended Humberside Collegiate Institute and York Memorial Collegiate Institute.
Document 9: McFly: On 16 March 2007, McFly guest starred in the "Top Gear" comic relief show "Top Gear of the Pops", where they were given a challenge to come up with a song from scratch without using the words 'love', 'baby', or 'heart', and including the words 'sofa', 'administration', and 'Hyundai'. Near the end of the show they performed the song they named 'The Top Gear Blues'. It was later renamed 'Sofa, Hyundai, Administration' and placed as a B-side on "The Heart Never Lies" single. On 23 June 2007, McFly made a cameo appearance in an episode of the science fiction series "Doctor Who". The episode "The Sound of Drums", saw the band appearing in a spoof party political broadcast, which featured testimonials from British celebrities such as McFly and Sharon Osbourne showing their support and trying to encourage others to "Vote Saxon!" in support of Mr Saxon (The Master played by John Simm) to become Prime Minister of the United Kingdom.
Document 10: Make a Scene: Make a Scene is the fourth studio album by English singer and songwriter Sophie Ellis-Bextor, released in Russia on 18 April 2011 by Universal Music Group and in the United Kingdom on 13 June 2011 by Ellis-Bextor's own record label, EBGB's. It is her first studio album since "Trip the Light Fantastic" (2007).
Document 11: Starlight (Sophie Ellis-Bextor song): "Starlight" is a pop song released by British singer-songwriter Sophie Ellis-Bextor as the sixth overall single from her fourth studio album, "Make a Scene". It was released on 5 June 2011, in the United Kingdom as a digital download, a week before the release of the album. Ellis-Bextor appeared on various talk shows to promote the single prior to its release. The song also served as the lead single in Australia and Italy, released on 23 September 2011 a week ahead of the album release there. It's her first single as an independent artist with her label EBGB's.
Document 12: It's On with Alexa Chung: It's On with Alexa Chung is an American live interactive talk and variety program that aired weekdays on MTV from June 15 to December 17, 2009. The show, a "successor" to MTV's "Total Request Live", was hosted by British model-turned-television personality Alexa Chung.
Document 13: India Jane Birley: Born in London, she is the daughter of Lady Annabel Vane-Tempest-Stewart, from her marriage to nightclub mogul Mark Birley. She has two brothers, Rupert (presumed deceased) and Robin; and three half-siblings, Zac, Jemima, and Ben Goldsmith from her mother's affair with James Goldsmith, the man who would become her second husband.
Document 14: Sophie Ellis-Bextor: Ellis-Bextor was born in London to Janet Ellis, who was later a presenter on BBC's children's television programmes "Blue Peter" and "Jigsaw", and Robin Bextor, a film producer and director: they separated when she was four. As a child, Ellis-Bextor occasionally appeared on "Blue Peter" alongside her mother, who presented the programme.
Document 15: Jess Glynne: Jess Glynne was born in Hampstead and raised in Muswell Hill, North London, in a Jewish family. Her father, Laurence Glynne, is an estate agent; and her mother, Alexandra (née Ingram), worked in A&R in the music industry. The family name was originally Goldstein, but her grandfather changed it to Glynne. She applied for the television show "The X Factor" when she was 15 years old, but dropped out of the audition process following a disagreement with the producers. She attended Rhodes Avenue Primary School, then attended Fortismere School, where she completed her A-levels in 2008, and took various jobs at a boutique, a fitness centre and a hairdresser's. After a period spent travelling the world, Glynne worked for a music management company in her late teens and began networking with songwriters and producers, eventually honing her artistry for four years.
ground_truth: Janet Ellis
sub_queries: Off & On >> performer Answer: Sophie Ellis-Bextor
Which lady gave birth to Sophie Ellis-Bextor ? Answer: Janet Ellis