Delia Catherine Keogh Birth/1851 Census

[airsle]

I have all records except birth and 1851 Census for this particular person so thought I'd ask the experts to double check I haven't missed anything.

Delia Catherine Keogh B1842 in Keoghville, County Roscommon to Ross E Keogh BCirca1800 in Athlone, Co Roscommon and Margaret Chadwick O'Fallon B1804 in Athlone, Co Roscommon.

Ross E Keogh was from a family that lived in Keoghville House, Taghmaconnell, County Roscommon. His parents were Edmond Keogh and Mary Fallon.  Ross and Margaret had four children, who were Mary Keogh, John Lawrence (born 1834), Daniel (1838) and Delia Catherine (1842). 

Delia married Robert Archibald Hurley in 1858 in Shoreditch, London.

Thank you in advance for any help and do let me know if any further information is needed!

[Maiden Stone]

Birth registrations didn't begin until 1864. Have you found her baptism?

Only fragments of 1851 census survive. There are some returns from 3 baronies in Roscommon.
www.census.nationalarchives.ie/pages/1851/Roscommon/
Click on name of a barony for list of civil parishes then on a parish name for townlands, then on townland name for census returns for that townland.
Alternatively use search form to do a surname search in Roscommon on 1851 census. I wouldn't bother putting in forenames, Delia may have been called something else and there's not likely to be many results to sift through.*
Another way of seeking for lost Irish census returns is to see if she requested a census search to prove her age when applying for a pension at age 70. Only people on low incomes qualified for pensions. Some were able to provide proof of age and didn't need to apply for a census search.
 Athlone was on both sides of the county boundary between Roscommon and Westmeath. 

Added. Search for Keogh in Roscommon on 1851 census, result nil. 

[Maiden Stone]

I suppose you already have information about Keoghville on Galway University Landed Estates website.
Taghmaconnell civil parish was in Athlone barony and Athlone PLU.

[shanreagh]

An Ancestry tree has her birth in Dublin  at 1836. This possibly/probably fits better with a marriage to Hurley in 1858. If she was married in 1842 it would have been at the age of 16 and while this did happen the marriage certificate usually had an annotation, unless she signed the certificate as being of full age? 
Do you have a copy of the marriage certificate? 

What religion was she?