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.