I was looking at the Mary Ellen Enderby marriage and it seemed a possibility.
However, I found a tree which has the marriage as 19th February 1910 at St Matthew, which came from Edward's army record. The record gives children as Mary Ellen, on 16th May 1910, and William Henry on 25th May 1915. The army record and second birth record both give Mary's maiden name as Enderby, although the marriage index is clearly Tiday.
The other puzzle is that there is no birth record for Mary Ellen Tiday or Enderby c1891 but, in 1901, there is a Lois Enderby in the same household as Nellie, so there seems to be a link.
David