Knight

HCR diary 18.3.1832 "went to the Aders - the Knights were there"
                      2.6.1832 "called on Mrs Aders - the Knights there"
                    10.8.1832 "went to Mrs Aders - Knight there - consequently not much"
Knight was a very common name and these were the only times they were mentioned in HCR diary in connection with the Aders. It was shortly before Aders' financial problems became public. Nevertheless I could make a stab at guessing this was the family of Charles Knight (DNB 1791-1873)