On 25 Oct 1760 King George II of Great Britain and Ireland (age 76) died at Kensington Palace. His grandson [her father] King George III of Great Britain and Ireland (age 22) succeeded III King Great Britain and Ireland. Duke Cambridge merged with the Crown.
On 08 Sep 1761 [her father] King George III of Great Britain and Ireland (age 23) and [her mother] Charlotte Mecklenburg Strelitz Queen Consort England (age 17) were married at Chapel Royal, St James's Palace. She by marriage Queen Consort England. He the son of Frederick Louis Hanover Prince of Wales and Augusta Saxe Coburg Altenburg (age 41). They were half second cousin twice removed. He a grandson of King George II of Great Britain and Ireland.
On 25 Apr 1776 Mary Hanover Duchess Gloucester and Edinburgh was born to King George III of Great Britain and Ireland (age 37) and Charlotte Mecklenburg Strelitz Queen Consort England (age 31).
On 29 Dec 1803 Godfrey Bosville Macdonald (age 28) and [her illegitimate sister-in-law] Louisa Maria La Coast Hanover (age 21) were married at Norwich, Norfolk [Map]. She the daughter of William Henry Hanover 1st Duke Gloucester and Edinburgh (age 60) and Almeria Carpenter (age 51). She a great granddaughter of King George II of Great Britain and Ireland.
On 25 Aug 1805 [her uncle] William Henry Hanover 1st Duke Gloucester and Edinburgh (age 61) died. His son [her future husband] William Frederick Hanover 2nd Duke Gloucester and Edinburgh (age 29) succeeded 2nd Duke Gloucester and Edinburgh, 2nd Earl Connaught.
On 22 Jul 1816 William Frederick Hanover 2nd Duke Gloucester and Edinburgh (age 40) and Mary Hanover Duchess Gloucester and Edinburgh (age 40) were married at St James's Palace [Map]. She by marriage Duchess Gloucester and Edinburgh. She the daughter of King George III of Great Britain and Ireland (age 78) and Charlotte Mecklenburg Strelitz Queen Consort England (age 72). He the son of William Henry Hanover 1st Duke Gloucester and Edinburgh and Maria Walpole Duchess Gloucester and Edinburgh. They were first cousins. He a great grandson of King George II of Great Britain and Ireland. 
On 17 Nov 1818 [her mother] Charlotte Mecklenburg Strelitz Queen Consort England (age 74) died.
On 29 Jan 1820 [her father] King George III of Great Britain and Ireland (age 81) died at Windsor Castle [Map]. His reign the third longest after Victoria and Elizabeth II. His son [her brother] King George IV of Great Britain and Ireland (age 57) succeeded IV King Great Britain and Ireland. Caroline of Brunswick Queen Consort England (age 51) by marriage Queen Consort England.
On 30 Nov 1834 [her husband] William Frederick Hanover 2nd Duke Gloucester and Edinburgh (age 58) died at Yattendon Castle [Map]. He was buried at St George's Chapel, Windsor Castle [Map]. Duke Gloucester and Edinburgh, Earl Connaught extinct.
On 10 Feb 1835 [her illegitimate sister-in-law] Louisa Maria La Coast Hanover (age 53) died at Bossall.
On 29 Nov 1844 [her former sister-in-law] Princess Sophia of Gloucester (age 71) died at Ranger's House Blackheath, Greenwich. She was buried at St George's Chapel, Windsor Castle [Map].
On 30 Apr 1857 Mary Hanover Duchess Gloucester and Edinburgh (age 81) died.
Paternal Family Tree: Hanover
Kings Wessex: Great x 21 Grand Daughter of King Edmund "Ironside" I of England
Kings Gwynedd: Great x 19 Grand Daughter of Owain "Great" King Gwynedd 1100-1170
Kings Seisyllwg: Great x 25 Grand Daughter of Hywel "Dda aka Good" King Seisyllwg King Deheubarth
Kings Powys: Great x 20 Grand Daughter of Maredudd ap Bleddyn King Powys 1047-1132
Kings England: Daughter of King George III of Great Britain and Ireland
Kings Scotland: Great x 15 Grand Daughter of Robert "The Bruce" I King Scotland
Kings Franks: Great x 17 Grand Daughter of Louis VII King Franks
Kings France: Great x 12 Grand Daughter of Charles "Beloved Mad" VI King France
Great x 4 Grandfather: George Hanover Duke Brunswick-Lüneburg 1582-1641
Great x 3 Grandfather: Ernest Augustus Hanover Elector Brunswick-Lüneburg 1629-1698 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Anne Eleonore Hesse Darmstadt Duchess Brunswick-Lüneburg 1601-1659 12 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 2 Grandfather: King George I of Great Britain and Ireland Great Grand Son of King James I of England and Ireland and VI of Scotland
Great x 4 Grandfather: Frederick Palatinate Simmern V Elector Palatine Rhine
10 x Great Grand Son of King Henry III of England
Great x 3 Grandmother: Sophia Palatinate Simmern
Grand Daughter of King James I of England and Ireland and VI of Scotland
Great x 4 Grandmother: Princess Elizabeth Stewart Queen Bohemia
Daughter of King James I of England and Ireland and VI of Scotland
Great x 1 Grandfather: King George II of Great Britain and Ireland Son of King George I of Great Britain and Ireland
Great x 4 Grandfather: George Hanover Duke Brunswick-Lüneburg 1582-1641
Great x 3 Grandfather: George Wilhelm Hanover Duke Brunswick-Lüneburg 1624-1705 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Anne Eleonore Hesse Darmstadt Duchess Brunswick-Lüneburg 1601-1659 12 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 2 Grandmother: Sophia Dorothea Hanover Queen Consort England 1666-1726 14 x Great Grand Daughter of King Henry "Curtmantle" II of England
GrandFather: Frederick Louis Hanover Prince of Wales Son of King George II of Great Britain and Ireland
Great x 4 Grandfather: Joachim Ernst Hohenzollern 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandfather: Albert Hohenzollern 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 2 Grandfather: John Frederick Hohenzollern 14 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 1 Grandmother: Caroline Hohenzollern Queen Consort England 15 x Great Grand Daughter of King Henry "Curtmantle" II of England
Father: King George III of Great Britain and Ireland Grand Son of King George II of Great Britain and Ireland
Great x 4 Grandfather: Johann Wettin II Duke Saxe Weimar 1570-1605 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandfather: Ernest "The Pious" Saxe Gotha I Duke Saxe Gotha 1601-1675 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Dorothea Maria Anhalt
Great x 2 Grandfather: Frederick Saxe Coburg Altenburg I Duke Saxe Gotha Altenburg 1646-1691 10 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: Johann Philipp Wettin Duke Saxe Altenburg 1597-1639 8 x Great Grand Son of King Edward III of England
Great x 3 Grandmother: Elisabeth Sophie Saxe Altenburg Duchess Saxe Gotha 1619-1680 9 x Great Grand Daughter of King Edward III of England
Great x 4 Grandmother: Elisabeth of Brunswick-Wolfenbüttel Duchess of Saxe-Altenburg 13 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 1 Grandfather: Frederick Saxe Coburg Altenburg II Duke Saxe Gotha Altenburg 1676-1732 11 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: John George Wettin Elector Saxony 1585-1656 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandfather: Augustus Duke of Saxe Weissenfels 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 2 Grandmother: Duchess Magdalena Sibylle of Saxe Gotha Altenburg 1648-1681 14 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 4 Grandfather: Duke Adolphus Frederick I of Mecklenburg-Schwerin 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandmother: Anna Maria of Mecklenburg-Schwerin 13 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Anna Maria of Ostfriesland 12 x Great Grand Daughter of King Henry "Curtmantle" II of England
GrandMother: Augusta Saxe Coburg Altenburg 12 x Great Grand Daughter of King Edward III of England
Mary Hanover Duchess Gloucester and Edinburgh 1776-1857 Daughter of King George III of Great Britain and Ireland
Great x 4 Grandfather: Duke John Albert I of Mecklenburg-Schwerin 11 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandfather: Duke John VII of Mecklenburg-Schwerin 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Anna Sophia Hohenzollern 11 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 2 Grandfather: Duke Adolphus Frederick I of Mecklenburg-Schwerin 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandfather: Duke Adolph Oldenburg of Holstein-Gotorp
Great x 3 Grandmother: Sophia Oldenburg 11 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 4 Grandmother: Christine Hesse 10 x Great Grand Daughter of King Henry "Curtmantle" II of England
Great x 1 Grandfather: Duke Adolphus Frederick II of Mecklenburg-Strelitz 13 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 4 Grandfather: Henry Duke of Brunswick-Dannenberg 11 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 3 Grandfather: Julius Ernst Duke of Brunswick-Dannenberg 12 x Great Grand Son of King Henry "Curtmantle" II of England
Great x 2 Grandmother: Maria Katharina 13 x Great Grand Daughter of King Henry "Curtmantle" II of England
GrandFather: Charles Louis Frederick Duke of Mecklenburg 14 x Great Grand Son of King Henry "Curtmantle" II of England
Mother: Charlotte Mecklenburg Strelitz Queen Consort England 15 x Great Grand Daughter of King Henry "Curtmantle" II of England