Well, there is a Brighton connection to 54 Walnut Tree Walk in 1851, as the head of household, Jane Parsons Luxford, was born there, according to the census.
Watkins's Commercial and General London Directory, 1852
Humphreys G. coal deal. &c. 52 Walnut tree walk, Lambeth
Anyway, it looks like George and Elizabeth's daughter Elizabeth (Sarah) may have died in 1851.