Thanks Carol!
This family is from Ireland so I cannot believe on how naive I am not even giving a thought to looking at UK BDM!
Eliza could possibly be English. I will have a look at the Census.
This child is Robert Turnbull, born in Dublin on 15th July 1879. I have found both him and his father on the Irish 1901 and 1911 Census but no trace of Eliza. If she is English, she may have returned to England - There has also been a name change from Turnbull to Manning between 1901 and 1911 which isn’t helping in my search!
Robert (the father) has recorded his home town in Waterford Co. Ireland on the Census so I’m thinking he must have travelled.
I will now shift from Ireland to England and see what I can find.
Many thanks again

Carolyn