6.11.1795 Sloper at Carr's with Carlisle / 16.1.1796 Sloper at Carlisle's / 23.5.1797 Slopers at Carlisle's / 6.10.1797 Sloper & Carlisle call / 27.5.1798 Sloper at Tooke's / 4.6.1798 Sloper & Carlisle call / 3.5.1800 adv Sloper senior at Carlisle's / 18.5.1800 miss Sloper at Tooke's / 16.7.1805 mesdames Carlisle White & Sloper & Mulready at tea / 29.1.1807 call on Sloper / 24.2.1807 again / 8.4.1807 again / 24.4.1807 call on Sloper: adv. Sutton / 6.5.1807 meet Sloper / 27.5.1807 call on Sloper (not seen) /  30.5.1807 again / 2.6.1807 meet Sloper & Keir / 1.12.1807 call on Sloper (adv. Walsh) / 2.12.1807 call on Sloper / 4.12.1807 again / 5.12.1807 meet Sloper / 25.4.1808 call on Sloper (not seen)
Because of the connection with Anthony Carlisle (DNB 1768-1840) it seems probable that the Slopers Godwin met were of the family of General Sir Robert Sloper (1729-1802). He married in 1752 Jane Willes (dau of John Willes DNB 1685-1761). They had four children, Jenny (born 1753 married 1777 Rev William Goddard, had one child Amelia and died 1784), John (1759-1787), Granby (born 1765 died 1835 Paris apparently unmarried and without children) and Robert Orby (born 1769 married twice, had five children and died 1828). Sir Robert also had an illegitimate family of six children by a woman who was probably born Sarah Stokes but was later known as Sarah Stokes Knowler. The oldest child Hetty married, as Hetty Stokes, in India in 1785 Pellegrin Treves (1760-1825). In her burial record (St George Hanover Sq 25.9.1826) her age was recorded as 37 but she must have been born around the same time (1769) as Sir Robert's youngest child by his wife, or earlier. In Sir Robert's will he excused himself for not leaving Hetty Treves anything, not for lack of affection but because she was well provided for. In the will of her presumed mother Sarah Stokes Knowler she wasn't mentioned at all. The other five children were Robert Stokes Sloper (1769-1845) the Rev George Sloper (1774-1855) Charles Stokes Sloper (died about 1806) Marcia (1784-1841) and Emily (born 1792). Sir Robert's will also left something to John Stokes (1750-1825) who like the General and his mistress was living at West Green, Hampshire (though he had previously lived in London) while the General's wife lived at the family seat at West Woodhay, Berks, so John Stokes was likely the brother of the General's mistress. When Sir Robert had returned from India in 1787 the newspapers noted the passengers on board the William Pitt from Bengal, including General Sloper & family, Rev Mr Goddard, and Mrs Knowler. Sarah Stokes Knowler died very shortly after Sir Robert in 1802, while his widow Jane Sloper died in 1804. In a Chancery suit of 1803 (Nat Arch C 13/1590/32) concerning the will of Sarah Stokes Knowler, Anthony Carlisle complained on behalf of Marcia and Amelia the two children still not of age (as their "best friend") against Robert Stokes Sloper, who was an attorney and an executor of the wills of the general and his mistress. Much later, in 1821, Carlisle was involved in an equity suit in the Court of Exchequer, in which Edward Goddard, son of the Rev William Goddard by his second wife, who was left an orphan at age 6 in 1798, complained against Robert Stokes Sloper, his wife and son, and Carlisle, as R S Sloper had become insolvent while caretaking young Goddard's inheritance. Carlisle took a neutral position but was clearly a close family friend.
The Slopers in 1807 and 1808 were all calls and not with Carlisle, but Robert Stokes Sloper, an attorney Godwin had perhaps already met, would seem a likely candidate even without the Carlisle connection. The Sloper entries before 1800 might have been Robert Stokes Sloper, or perhaps William Charles Sloper (1736-1824) younger brother of Sir Robert Sloper, who was MP for St Alobans 1780 to 1790 and who married in 1774 Amelia, daughter of Jonathan Shipley (DNB 1713-1788) bishop of St Asaph. They had one daughter Amelia, who married Charles Warren (qv) in 1813, and she may have been the miss Sloper at Tooke's in 1800, the only other likely Miss Sloper from this family would have been Marcia (see above). The Sloper senior at Carlisle's in 1800 was probably Sir Robert - he could have been senior (as older brother) to William Charles. or (as father) to Robert Stokes. The mesdames Carlisle, White and Sloper in 1805 could have included a miss and/or a mrs Sloper. Robert Stokes Sloper had married (as a bachelor) Maria Lane in 1804 so it was possibly her. R S Sloper also had a son George Dyke Sloper, also an attorney, who must have been born about 1785 when R S Sloper was only 16; he might also have been the Sloper of 1807.

Work notes: 
Boyle's 1794 Wm & Mrs S 10 South Audley St George Townsend Sloper adm Middle Temple 28.3.1776 eldest son of Matthew of Tetbury Glos, called to bar 1783 Wm Chas S PCC 1824 of Sundridge, Kent married 29.11.1774 at Twyford Amelia dau of Jonathan Shipley DNB 1713-88 bishop of St Asaph their dau Amelia marr Charles Warren 9.7.1813 in house of Lady Jones (widow of Sir William Jones, and another daughter of Jonathan Shipley) in South Audley St, another sister Catherine Louisa Shipley's will PCC 1840