There is a Pauper Examination in Chelsea in 1879/1880 for Margaret Blake aged 34, widow of John, listing the following children: Mary 15, George 13, Hy 11, James 11, John 8, Annie 1y 4m.
John had died 4 months earlier. Various previous addresses are listed, some in Fulham, others in Chelsea. John Sr is noted as born Ireland, father Henry. Margaret's parents given as George (deceased) & Elizabeth Darcy. Elizabeth's address was 42 Oakham Street.
Link below, but to find it the long way:
London, England, Poor Law and Board of Guardian Records, 1738-1930 > Kensington & Chelsea > Chelsea > Depositions > Pauper Examinations Jan 1879-Jan1885 > Image 87 of 316.https://www.ancestry.co.uk/interactive/1557/31363_a109794-00...
I'll see if I can find anything else, but as there are thousands of records that haven't been transcribed it can sometimes be like finding a needle in a haystack.