With the information from the 1911 census that my great-great-grandfather
James Thomas Stocking was widowed by then, and that his youngest son appears to have been born in 1902, I searched the death registers online again to see if I could track down the death of Alice Mary Stocking, my great-great-grandmother. And I think I may have done. In 1907 there is a death index entry in FindMyPast for the March quarter for an Alice Stocking, aged 49 (1d 588). This would fit with her birth year of around 1857, and the family's home at Bowles Road in Camberwell. I've ordered the certificate, so here's hoping it's the correct one.