Hi Jan,
My grandmother Susannah Juan would have been the sister of your grandmother and her twin. They lived in Poplar. The other brothers and sisters were Mary, Juaquin, Arthur, and Esther who died age 5. Their parents were Juaquin Juan and Mary Ann Dixon. Our Great grandfather Juaquin was from Barcelona in Spain . He died in 1909. On his mariage certificate he gives his fathers name as Juaquin as well. Mary Ann's parents were George Dixon from Deptford and Mary Ann Simpson from North Wales. George's parents were Michael and Phillis Dixon.
I havn't got any further back than that but I keep trying.
My father grew up on the Isle of Dogs but moved to Plumstead Common after he married my mother in 1941.
Hope this is of help.
Regards
Frances