HCR 12.5.1826 HCR's guests to supper "Flaxmans, Masqueriers, a Miss Forbes, Blake, Sutton Sharpe"
26.5.1829 at Brighton Mrs Masqueriers youngest brother just returned from Italy "Some of the family of Sir Charles Forbes came in and a Miss Ashburnham"
As G E Bentley pointed out in Blake Records p 446 note, Robinson's small appointments diary lists all the names on 12.5.1826 above except Miss Forbes, so it is reasonable to assume the Masqueriers brought her. Mrs Masquerier was born Rachel Forbes-Mitchell, so it may have been one of her relations (her father had assumed the Mitchell bit). Going from the genealogy in Burke's Peerage (Forbes of Craigievar, later Baron Sempill) it seems she had no unmarried sisters and her oldest nieces would have been only ten years old. She had many female cousins but all of them married, mostly before 1826, and their daughters would also have been no older than ten. There was one cousin, the youngest daughter of William Forbes, Jane born 1795 who married the Rev Dr William Carpenter, I haven't found the date of their marriage, but it was probably after 1826, and two other cousins, daughters of Arthur Forbes, Isabella born about 1808 who married Beauchamp Newton in 1834, and Christina Frances, born 1810 who died unmarried in 1899. Mrs masquerier's youngest brother, according to Burke's, was named Mansfield. Another possible Miss Forbes, though not apparently a near relation of Mrs Masquerier, was Katherina Stewart Forbes, daughter of Charles Forbes (DNB 1773-1849), who was born 24.1.1808 in Bombay and died unmarried 28.12.1891. Her father's DNB article says he had one son and 4 daus, History of Parliament Online says 4 sons and 2 daus, and Burke's Peerage 1828 listed 4 sons and Katherine, who would have been only 15 when the Morning Post of 15.10.1823 reported that a lithographic artist of some note, who was a foreigner, had been introduced to Sir Charles Forbes, her father, "through the recommendation of the amiable Miss Forbes". This was G Glauci. At the time of the 1871 census Katherine Forbes was living at Chester House, Wimbledon and her visitor was Eliza Sharpe (DNB 1796-1874), miniature and subject painter. Miss Forbes daughter of Charles Forbes MP was one of the subjects exhibited by Eliza's sister Louisa Sharpe (DNB 1798-1843) at the Royal Academy in 1826, all of which might suggest an interest in art which could have led her to want to meet William Blake (DNB 1757-1827)