The same person with two different names ot twins?

[OutInTheCold]

I've discovered 2 relatives who are either twins, or the same person.

Mary Jane Hornsby (born October 21st 1874, Cork) daughter to Colour Sergeant Joseph Hornsby and Martha Francis Mcdowell. I have the Irish Civil Group Registration ID is 8520585, but no death records.
Adelina Hornsby (died 10th September 1878 in Camp Muntaznuggar, Fyzabad, Andhra Pradesh, India) daughter of Sergeant Major Joseph Hornsby 1st/25 KOB on death information but no birth details.
Death information states she was 3 and 11/12 years, same birth as Mary Jane?
The parents also had an earlier daughter Mary born in Preston in 1866 who married.

Could this be a mishearing of a name when the details were taken down?

[Kiltaglassan]

Here's the birth record.
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1874/03119/2143912.pdf

There's no twin above or below the record and no time of birth indicated.

It's likely that she was then called Adelina (and not Mary Jane).......it often happened that a child got a new first name. Unlikely to be mis-heard.

[OutInTheCold]

That's the record I have, checked both the Church and Civil and no other listing, however in the Army Births and Baptims there is an Adelina Hornsby born in Cork 1874 (to the 25th Regiment) BMD_OVS_REG1_001495, but no Mary Jane listed on this.
So the name change could be for Army reasons?
Mary-Jane to please the Irish side of the family?

[Kiltaglassan]

Mary-Jane to please the Irish side of the family?

Indeed......here's their marriage in 1860. Her father, John McDowell a sergeant in the Constabulary (R.I.C.?)
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1860/09582/5474230.pdf

[OutInTheCold]

Mary-Jane to please the Irish side of the family?

Indeed......here's their marriage in 1860. Her father, John McDowell a sergeant in the Constabulary (R.I.C.?)

Mary-Jane Adelina Hornsby it is, to give her her full name. . .
Many thanks