4.11.1807 meet Pilcher, w. M J / 3.8.1809 write to S Pilcher / 30.10.1809 Pilchers dine
Edward Paul Pilcher 1763-1826 had married Mary Jane Godwin's sister Sophia in 1792. It was eight years after Godwin's second marriage that the Pilchers first visited the Godwins (according to the diary). The Pilcher children later became frequent callers on the Godwins.
Their children (first three all baptised together in 1796) were 1) Edward, who probably died young, as he was not mentioned in his father's will of 1826, nor apparently in Godwin's diary 2) Peter who married in 1826 Emma Mary Edgcumbe and died in 1831, and 3) Sophia, who married Henry George Salter in 1826; he became a vicar but fell into debt and died in 1862 at Boulogne and she lived with her son, vicar of Donington, Shropshire, and died in 1872.
7.12.1826 Salter married / 19.2.1827 Salters au soir / 5.3.1831 Salter tea & supper / 26.5.1834 Salter au soir
4) Henry Incledon baptised 1799 and died in New South Wales in 1845 and 5) Frances Incledon, who died in 1820 in the 20th year of her age. Henry was a solicitor in London in partnership with William Cheek Bousfield in 1826 and fathered at least one child on Eliza Bradley in 1827 before they left for Australia. I couldn't find their marriage record.
24.11.1810 call on Bousfield / 27.11.1810 again / 24.1.1826 W(illiam) calls, from Bousfield
In the early 1810s S Pilcher or even S P usually meant Godwin's sister in law, otherwise Mrs Pilcher, but in the 1820s it usually meant her daughter Sophia. On its own Pilcher usually meant Edward Paul Pilcher. Peter could be P P or P Pilcher. Henry could be H P or H Pilcher. Frances could be F P or F Pilcher.
23.11.1815 theatre; adv. Surrs & E P / 20.9.1820 Sadler's Wells; adv. Surrs & EP / 4.3.1824 sup at H P's, w. E P, C Landseer & W(illiam) / 8.3.1830 theatre; adv. E P
There were only four instances of E P in Godwin's diary after the death of E P Cooper in 1803, three met at the theatre of which two were with the Surrs. I think this was Elizabeth, the wife of Richard Phillips, whose sister was Mrs Surr. The other E P was probably Edward Prentis DNB 1797-1854. In the diary in 1824 he was several times in the company of C Landseer, H(enry) P(ilcher) and W(illiam Godwin jr).
Edward Paul Pilcher was the son of Edward Pilcher, JP, of Cobham, Kent, will PCC 1800, who married Frances Incledon at Bath in 1760.  His will mentioned three daughters (Maria = George Torriano, Jemima = Joseph de Courcy L'Affan, MD, and Henrietta = Capt. John French, 73rd Foot) as well as his son Edward Paul and a probable illegitimate son Francis Scrimes Pilcher
Peter Pilcher may have gone to sea.
19.1.1812 P P, the Bombay, ca, Montg. Hamilton / 10.2.1812 P P sups and sleeps / (Public Ledger 7.3.1812 "Sailed the Bombay, Hamilton, for India" then Peter next appeared on) / 7.6.1813 P P sups.
8.12.1818 S & P Pilcher arrive / 4.3.1819 S Pilcher departs, 12 weeks 2 days.
Did I detect a note of irritation?