Question: Which 2010 book was written by the eldest child of Queen Elizabeth II?

Context articles: George VI and Queen Elizabeth Memorial
Sapphire Jubilee of Queen Elizabeth II
Queen Elizabeth Hospital
Camilla, Duchess of Cornwall
Queen Elizabeth cake
Queen Elizabeth II Golden Jubilee Medal
Baron Plunket
Black spider memos
Harmony: A New Way of Looking at Our World
Charles, Prince of Wales

The George VI and Queen Elizabeth Memorial, situated between The Mall and Carlton Gardens in central London, is a memorial to King George VI and his consort, Queen Elizabeth The Queen Mother.
 Completed in its present form in 2009, the memorial incorporates an earlier, Grade II-listed statue of George VI by William McMillan, unveiled by his daughter Queen Elizabeth II in 1955.
 The reconfigured memorial, which includes a statue of the Queen Mother by Philip Jackson, relief sculpture by Paul Day and an architectural setting by Donald Buttress and Donald Insall, was unveiled by Elizabeth II in 2009.
On 6 February 2017, the Sapphire Jubilee of Queen Elizabeth II, marking sixty-five years of her reign, occurred.
 The longest-reigning monarch in British history, Queen Elizabeth II was the first British monarch to have a sapphire jubilee.
 This Jubilee featured blue stamps from the Royal Mail, commemorative coins from the Royal Mint, and a reissue of an official 2014 portrait of Queen Elizabeth II by David Bailey.
 In this official portrait the Queen wears sapphire jewellery which she received as a wedding present from her father.
 The Jubilee also involved a gun salute at the Tower of London, a gun salute in Green Park, gun salutes in several other places around the United Kingdom, and the ringing of the bells in Westminster Abbey.
 Theresa May, the Prime Minister of the United Kingdom, congratulated Queen Elizabeth II in regard to the occasion, saying in part, "I know the nation will join with me today in celebrating and giving thanks for the lifetime of service Her Majesty the Queen has given to our country and to the Commonwealth."
Queen Elizabeth Hospital or Queen Elizabeth's Hospital may refer to one of several institutions named after Queen Elizabeth I, Queen Elizabeth II or Queen Elizabeth the Queen Mother:
Camilla, Duchess of Cornwall, ("née" Camilla Rosemary Shand, previously Parker Bowles; born 17 July 1947), is the second wife of Charles, Prince of Wales, the eldest child and heir apparent of Queen Elizabeth II.
 Instead of using the title of Princess of Wales, she uses the title Duchess of Cornwall, her husband's secondary designation.
 In Scotland, she is known as the Duchess of Rothesay.
 In the event of Charles acceding to the throne, Camilla would become a queen consort; however, an official statement issued by Clarence House on the day of her marriage to Charles announced that she would be known as the Princess Consort.
Queen Elizabeth cake is a dessert cake prepared with typical cake ingredients and a shredded coconut icing.
 It is sometimes served with tea.
 Queen Elizabeth cake is named after Elizabeth II.
 It may have originated in 1953 for the coronation of Elizabeth II, and another account holds that it was invented for the 1937 coronation of King George VI and the Queen Mother Queen Elizabeth.
The Queen Elizabeth II Golden Jubilee Medal (French: "Médaille du jubilé de la Reine Elizabeth II" ) or the Queen's Golden Jubilee Medal was a commemorative medal created in 2002 to mark the fiftieth anniversary of Elizabeth II's accession.
 The Queen Elizabeth II Golden Jubilee Medal was awarded in Canada to nominees who contributed to public life.
 The Queen's Golden Jubilee Medal was awarded to active personnel in the British Armed Forces and Emergency Personnel who had completed 5 years of qualifying service.
Baron Plunket, of Newtown in the County of Cork, is a title in the Peerage of the United Kingdom.
 It was created in 1827 for the prominent Irish lawyer and Whig politician William Plunket.
 He served as Lord Chancellor of Ireland from 1830 and 1834 and again from 1835 to 1841.
 His eldest son, the second Baron, was Bishop of Tuam, Killala and Achonry between 1839 and 1866.
 He was succeeded by his younger brother, the third Baron.
 He was a barrister.
 His eldest son, the fourth Baron, served as Archbishop of Dublin between 1884 and 1897.
 He was succeeded by his eldest son, the fifth Baron.
 He was a diplomat and held office as Governor of New Zealand between 1904 and 1910.
 His grandson, Patrick, the seventh Baron, was Equerry to both King George VI and Queen Elizabeth II.
 He was succeeded by his younger brother, Robin who died in 2013 and was in turn succeeded by his nephew, Tyrone who was a Page of Honour to Queen Elizabeth II.
The "black spider" memos are letters and memos written by Charles, Prince of Wales, to British government ministers and politicians over the years.
 As the modern British monarch remains politically neutral by tradition, the letters are controversial because of Prince of Wales' position as the eldest child of the British monarch Queen Elizabeth II and heir apparent to the British throne.
Harmony: A New Way of Looking at Our World is 2010 book written by Charles, Prince of Wales with Tony Juniper and Ian Skelly.
 The book focuses on the world's environment which includes climate change, architecture and agriculture which the Prince of Wales usually addresses.
 The book has been translated into many different languages.
 There is also a children's edition of "Harmony".
Charles, Prince of Wales (Charles Philip Arthur George; born 14 November 1948) is the eldest child and heir apparent of Queen Elizabeth II.
 Known alternatively in Cornwall as Duke of Cornwall and in Scotland as Duke of Rothesay, he is the longest-serving heir apparent in British history, having held the position since 1952.
 He is also the oldest person to be next in line to the throne since Sophia of Hanover (the heir presumptive to Queen Anne), who died in 1714 at the age of 83.