mrs Spencer adv at Chandler's 28.5.1798 / 2.5.1800 Milton Gallery adv C Moores (& W Spencer) / 10.10.1806 W Spencer at Fox's funeral (wrongly transcribed as W Spences in GD website) / 18.12.1806 call on Rogers adv W Spencer / 28.3.1818 Spencer dined at Aldis's
The three W Spencer entries in 1800 and 1806 were quite likely William Robert Spencer DNB 1770-1834 who spent his last years from 1825 in Paris in poverty and ill-health so can't have been the Spencer whom Godwin met at the theatre 27 times between 1828 and 1836 (which I haven't included above). He had married Susan, the daughter of Count Francis Jenison Walworth and widow of Count Spreti on 13.12.1791 so she could perhaps have been the mrs Spencer of 1798 (see Farington diary p3086) and even the mrs Spencer at  Rickman's 14.6.1834 ( a few months before the death of W R Spencer whom the DNB states was survived by his wife). There were very probably other possible Spencers, particularly for the isolated 1818 entry and the two mrs Spencer entries