Agnes Loudon was born on August 25, 1832. She was the only child of Jane Loudon and John Claudius Loudon. On December 26, 1858, Agnes married Markham Spofforth. She died in June 1863, shortly after the birth of their third child. She is cast as the fictional author of The Claudians: John Claudius Loudon and Claudius Buchanan, published on Kindle.
Bea Howe writes a good deal about Agnes in her book, Lady with Green Fingers: The Life of Jane Loudon, and explains that: 'It would have been difficult to write my biography of Jane Loudon without the aid of the diary kept by her only child, Agnes, between the years 1849 and 1863.' Howe's view, which I share, is that in 1832 'Jane knew that she was going to have a child and her cup of personal happiness was full.' Not having seen Agnes' diary I will quote from Bea Howe:
'So little Agnes became the lively pivot of the Bayswater household. She was a pretty, beguiling child of eleven, given to sudden dreamy moods... In spite of her childish lack of concentration, though, shad a warm, impulsive heart and enormous charm. As she confessed later in life, "I was spoilt not only by my own dear Mother but by all those who came to the house because they wished to pleas Papa and thought that the surest way."... One day, she told Mama, she would be a famous authoress and earn a great deal of money to pay the bills.'
'For Christmas, 1848, Jane gave Agnes a tooled leather album worked in a flowery pattern of forget-me-nots, roses, mistletoe berries and holly leaves to denote the four seasons of the year. Inscribed in gold letters was the owner's name, AGLES LOUDON, and the date 1st January, 1849. All through his life, Jane told her daughter, dear Papa had kept a day-by-day journal, however tired he was or busy. Clasping her album excitedly to her heart, Agnes promised to do likewise.'
Agnes married Markham Spofforth in 1858 and died soon after the birth of her second child, in 1863. She is buried beside her parents in Kensal Green Cemetery. Her husband, Markham Spofforth, was a Conservative Party agent who worked closely with Benjamin Disraeli to restore the fortunes of the party. He married again and is buried in Yorkshire.

The wording on Agnes Loudon's grave, in Kensal Green Cemetery, is below. It is taken to mean that Markham Spofforth was also buried there but the word 'also' could apply to 'In Memory' rather than to 'buried.'
In
memory of
Agnes
the beloved wife of
Markham Spofforth Esq.
of Porchester Terrace
and of Howden, Yorkshire,
only daughter of
John Claudius and Jane Webb Loudon
Died 13 June 1863, Aged 32 years.
Also of
Beatrix Loudon Spofforth
daughter of
Markham and Agnes Spofforth
Born August 20 1860
Died August 20 1861
Buried
in the church
at Howden.
"Run now, I pray thee, to meet her and say unto her
is it well with thee? _ Is it well with the child
and she answered, it is well."
Also of Markham Spofforth
Born 14th March 1825 Died 26th January 1907