Here's the puzzle. Emma White, later Emma Double, appears as such on her marriage cert and all relevant censuses from birth to 1891. One of her daughters, Ada, appears in relevant censuses 71,81,91 as Ada Double and then later as Ada Birchall. However, in 1901, Emma, now a widow living in St Ives with the family of another daughter, appears as Emma E Double. In the same census, Ada, living in Fulham with her husband, appears as Ada E Birchall. In 1911, Emma now is recorded as Emma Edgcumbe Double. Ada died in 1903, her death is recorded in the register in Wandsworth as Ada Edgcumbe Birchall. So - assuming the "E" in 1901 stood for Edgcumbe, where the Sam Hill did it come from. There is no Edgcumbe connection in any other sibling or in anywhere else I've looked related to the 2 ladies. Theories (or even explanations) welcomed!
MaxD