How about this one for the missing twin elsie in 1901.. strangely struggling to trace this family too. 
Cottage in Wright Nursery, Turner Road, Lee, Lewisham, London & Kent, England
Charles   Cooper   Head   Married   Male   33   1868   Nursery Gardener   High Wycombe, Buckinghamshire, England
Ellen   Cooper   Wife   Married   Female   43   1858   -   Aston Clinton, Buckinghamshire, England
Florence   Warner   Step Daughter   -   Female   10   1891   -   North Kensington, London, England
Elsie   Warner   Step Daughter   -   Female   7   1894   -   North Kensington, London, England
Edith   Warner   Step Daughter   -   Female   5   1896   -   North Kensington, London, England
Elsie   Stevens   Grand Daughter   -   Female   1   1900   -   North Kensington, London, England
Who's granddaughter however I do not know, Ellen cooper is younger than John just a couple more year older than Emily.