We'd need a punt on the certificate, but I wouldn't be surprised that wishful thinking proved not to be correct.
To refresh our memories, which are the 7 children you have for Nathan and Mary Ann (to save me going all though the back posts) as I could only find 6 quickly 
Mary Ann (alive 1911)
Bertha (alive 1911)
Albert Sydney (alive 1911)
Lizzie (alive 1911)
Alice (dec by 1911)
Arthur (dec by 1911)
Casalguidi 
We hypothesised that the Nathaniel Evenden shown on Familysearch on a submitted entry as being the son of Nathan and Mary Ann (Polly) might be right - I found the birth ref (Jan qtr 1881 Malling, Kent) so the child actually exists (although I appreciate that without the certificate it's a guess rather than proven that he belongs to our family).
It's a tempting thought, though, as Mary Ann is with her father Richard Corke in the 1881 with an infant, and this Nathaniel could be him.
Can't, however, find a death for a Nathaniel Evenden/Cork(e)/Cooley between 1881 and 1911.
So this is the seventh child, we think, of the eight, and Sluggie refers to seeking the last one.
Thanks for sorting out Polly born 1897. As I said originally, it was just a tempting possibility, but evidently - as so often - wrong!