Why is her birth registration missing?

The adoption theory is neat - and highly possible, perhaps the vicar was seen as an appropriate person to adopt - when did Emma Coppen die?
If she died in childbirth (and James Almond had no other family alive nor in the immediate area) perhaps the adoption idea becomes more feasible?

Really I suppose you would need to discover if all those missing from the records have a similar corresponding record of a child who "vanished into mid air" as it were. That might be hard to find!

 

My 2x great-grandparents arrived in Birmingham from Ireland in the mid 1800's. Their first son was born in Ireland and Christened in the Catholic Church. Their 2nd. son James was born in 1855 and registered in Birmingham. There followed two daughters, Ann ( my Great.Grandmother) and Elizabeth. Ann was born 26 June 1861 and Christened in St. Peter's Catholic Church on 21 July 1861.
Elizabeth was born 10 March 1863 and Christened on 22 March 1863, also in St Peter's Church. I searched, with every combination of names I could think of, but could not find any birth registration for either girls. Then I contacted the genealogist at the local register office who did a very thorough search for me (spreading the search to surrounding registration districts). Nothing was found. - Thinking 'outside the box', I have concluded that as the girls had been christened in the Roman Catholic Church their parents considered that was sufficient record (as girls) of their birth and parentage; while their brother James was not only Christened but his birth also registered as required.
I'm aware this has no link to the family under discussion, but thought it another take on non registration.