Porter 2.4.1797 at Mary Robinson's / 4.6.1797 at Horseman's, Oxford / 27.4.1800 adv at Mary Robinson's (& Northcote). In Godwin's 1796 list for 1800 in position which might have referred to any of the 1800 entries / 28.4.1800 at RA exhibition / 2.5.1800 Porter's Seringapatam / 3.5.1800 adv at Bedford House / 13.5.1800 meet Porter / 17.5.1800 sup at Hoare's with N(orthcote) O(pie) Reynolds. Chalmers, Porter / 11.6.1800 Mary Robinson's with Northcote & 4 Porters / 18.6.1800 call on Northcote; meet Porter / 8.3.1802 Porter at Fuseli's lecture / 31.7.1802 theatre adv R K Porter / 3.1.1804 theatre adv col Porter / 11.10.1808 Walsh Porter's pictures / 30.3.1832 miss Porters at Leicester Stanhope's / 24.10.1833 miss Porter there / 11.11.1833 missPorter at Lady Stepney's / 14.11.1833 m Porter at Lady C Bury's / 28.6.1834 miss Porter (& Skinner) at Lady Stepney's / 18.10.1834 adv mrs Skinner & Ja Porter at Godwin's / 2.3.1835 mesd Skinner & Porter at Leicester Stanhope's / 30.3.1835 2 miss Porters at Skinner's
Walsh Porter in 1808 was Pierce Patrick Walsh Porter will PCC 1812 of St James Westminster.
Porter at Horseman's, Oxford was probably either Joseph Porter son of John of St Bees Cumberland adm Magdalen hall 16.1.1795 age 17 died 2.11.1833 will PCC 1833, Robert Porter son of William of Wigan, Lancs adm Brasenose 23.5.1792 age 18 BA 1796 died 25.3.1838 will PCC 1838, or William Warren Porter son of Moses of Clapham Surrey adm St John's 1.7.1794 age 18 died 14.6.1804 (Alum Ox)
First entry at Mary Robinson's 1797 might have been Stephen Porter, eldest son of David (will PCC 1819, twice) of Litle Welbeck St, Marylebone, sizar of Trinity Hall Cambridge 1790 who translated Kotzebue's Love Child in 1798 and was one of over 30 Cambridge undergraduates, mostly from Trinity Hall, a sort of fan club who subscribed to Mrs Robinson's Poems in 1791. Or perhaps Robert Ker Porter (see below) who had just arrived in London but not yet achieved celebrity, while by the 1800 entries he had reached instant fame.
All the other entries above probably referred to Robert Ker Porter DNB 1777-1842 (as noticed in GD website in the event tag of 2.5.1800 but not in a person record), his brother Col Porter (died 1811 aged 38 Isle of Man), and his sisters ( two of whom were Jane Porter DNB 1776-1850  and Anna Maria Porter DNB 1778-1832).  Another possible Colonel Porter was the MP George Porter 1760-1828 (History of Parliament) a Colonel in the militia and generally referred to in parliamentary reports as Colonel Porter