HI..Yes I've searched that whole Whittington family. Agnes Kate had about 10 siblings, some died before 1900 and a few of them I traced and found some living rellys but they don't want to talk..??. Hilda was born 1904 and her mother Agnes Kate married Frederick Langford in 1906, April 26 in St John Deptford, London and never had children. Agnes Kate was born in 1880, Lewisham Kent. I think in the early census Agnes Kate was known as Kate A. Whittington.
I have Agnes Kate's marriage certificate and Death certificate.
Thanks again Jenny for your proding