I'm just thinking aloud here .. ..
Birth, Sept 1888
Sarah Turner
Tendring, Vol 4a, page 485
Therefore Sarah was still only 22 when your nan was born?
You will hate me for stating the obvious but I think the 1911 census could hopefully throw up a lot of answers - it's a pity she couldn't have been born a few months earlier though!
Marriage, Sept qtr 1914
George Dye
Sarah Turner
West Ham, Vol. 4a, page 434