Lady Diana Beauclerk

Lady Diana Beauclerk ("née" Lady Diana Spencer; other married name Diana St John, Viscountess Bolingbroke; 24 March 1734 – 1 August 1808) was an English noblewoman and artist.
Early life.
She was born into the Spencer family as the daughter of Charles Spencer, 3rd Duke of Marlborough (1706–1758), and the Honourable Elizabeth Trevor (d. 1761). Her siblings were George, Charles, and Elizabeth. Her grandmother was the formidable Sarah Churchill, Duchess of Marlborough. She was raised at Langley Park, Buckinghamshire, where she was introduced to art at an early age. Joshua Reynolds, an artist, was a family friend.
Marriages and children.
On 8 September 1757, she married Frederick St John, 2nd Viscount Bolingbroke (1734–1787). From 1762–1768 she was Lady of the Bedchamber to Queen Charlotte. She became widely known as 'Lady Di' (as did her namesake in the early 1980s, before she became Princess Di).
She had four children during this first marriage:
Finding herself in a desperately unhappy marriage to the notoriously unfaithful Viscount Bolingbroke, Lady Di overturned convention. She left her husband and maintained a secret relationship with her lover, Topham Beauclerk.
In February 1768 Bolingbroke petitioned for divorce on grounds of adultery ("criminal conversation"). The petition required an act of parliament, which was passed the next month.
Within two days, she married Topham Beauclerk of Old Windsor. They had three children: 
Friends.
Their circle of friends included Samuel Johnson, Georgiana Cavendish — who maintained a glittering salon — Edward Gibbon, David Garrick, Charles Fox, James Boswell and Edmund Burke.
Fanny Burney recorded in her diary the feelings of Edmund Burke about Lady Diana after the death of Topham Beauclerk: From the window of the dining-parlour, Sir Joshua [Reynolds] directed us to look at a pretty white house which belonged to Lady Di. Beauclerk.
"I am extremely glad," said Mr. Burke, "to see her at last so well housed; poor woman! the bowl has long rolled in misery; I rejoice that it has now found its balance. I never, myself, so much enjoyed the sight of happiness in another, as in that woman when I first saw her after the death of her husband. It was really enlivening to behold her placed in that sweet house, released from all her cares, a thousand pounds a year at her own disposal, and — her husband was dead! Oh, it was pleasant, it was delightful to see her enjoyment of her situation!"
"But, without considering the circumstances" said Mr. Gibbon, "this may appear very strange, though, when they are fairly stated, it is perfectly rational and unavoidable."
"Very true," said Mr. Burke, "if the circumstances are not considered, Lady Di. may seem highly reprehensible."
He then, addressing himself particularly to me, as the person least likely to be acquainted with the character of Mr. Beauclerk, drew it himself in strong and marked expressions, describing the misery he gave his wife, his singular ill-treatment of her, and the necessary relief the death of such a man must give. 
On the other hand, James Boswell records that Samuel Johnson said of her (in 1773), "The woman's a whore and there's an end on't."
Artistic work.
Diana eventually helped to support herself by painting. She was a highly gifted artist who was able to use her scandalous reputation as an adulteress, aristocratic woman to further her career as a painter and designer. She painted portraits, illustrated plays and books, provided designs for Wedgwood's innovative pottery, and decorated rooms with murals. Championed by her close friend Horace Walpole, whose letters illuminate all aspects of her life, she was able to establish herself as an admired artist at a time when women struggled to forge careers.
She illustrated a number of literary productions, including Horace Walpole's tragedy "The Mysterious Mother", the English translation of Gottfried August Bürger's "Leonora" (1796) and "The Fables of John Dryden" (1797). After 1785 she was one of a circle of women, along with Emma Crewe and Elizabeth Templetown (1746/7-1823), whose designs for Josiah Wedgwood were made into bas-reliefs on jasper ornaments.
Later life, death, and legacy.
Her second husband died in 1780 and, due to restricted finances, she began to lead a more retired life. She died in 1808 and was buried in Richmond.
In the mid-1990s a portrait of her hung in Kenwood House, on Hampstead Heath in London, with the caption: "Lady Diana Spencer, known chiefly for the unhappiness of her first marriage." Such a caption is unfair for such a remarkable, strong woman.