Attempting to confirm information about Margaret Cullinane

Hello, I am trying to confirm my research about my Great, Great-Grandmother, Margaret Hayes (née Cullinane). 

Baptism: 29 June 1852 in Clonakilty, Cork. Unknown birth date but suspected Baptism information was found here: Ireland, Catholic Parish Registers, 1740-1900. Father was Timothy Cullinane Johanna Long was the Mother. On her City of Boston, Massachusetts Death Certificate it states that Timothy Cullinane was her father but gives no maiden name for mother, only states that Johanna was her mother.

Marriage: to John Hayes: 1 March 1870 Clonakilty, County Cork, Ireland taken from Ireland Civil Registration, 1845-1913

John and Margaret had 7 children that I can account for there may be one that I am missing, possibly named Joanna Hayes (Hease). 

Children:

1. Ellen Hayes Smith- Birth 26 JUNE 1871 • Clonakilty, Cork, Ireland Death 30 JUNE 1920 • Medford, Massachusetts

2. John J. Hayes- Birth JUNE 1873 • Clonakilty, County Cork, Ireland Death 26 JAN 1947 • Dorchester, Massachusetts

3. Laurence J. Hayes- Birth 27 DEC 1874 • Cork, Ireland Death 9 APR 1947 • Grafton, Massachusetts

4. Hannah Hayes Anthes- Birth 1879 • Ireland Death 16 AUG 1906 • Boston, Massachusetts

5. Stephen J. Hayes- Birth 26 DEC 1880 • Clonakilty, County Cork, Ireland Death 22 JUN 1926 • Mare Island Navy Yard Hospital, California

6. Patrick J. Hayes- Birth 16 JANUARY 1885 • Boston, Suffolk, Massachusetts Death 12 APR 1920 • New Haven County, Connecticut

7. Margaret T. Hayes Wilson- Birth 5 DEC 1887 • East Boston, Suffolk, Massachusetts Death 30 OCT 1927 • Malden, Massachusetts

Death: Death 6 MAY 1934 • Dorchester, Massachusetts

I have researched all of these ancestors through Ancestry.com, Family Search.com, Boston Catholic Diocese Records, Massachusetts issued death certificates, family history and photographs. However, I am not a professional researcher and have exhausted my abilities. Could someone perhaps give me some advice on how to confirm a birthdate for Margaret? Her tombstone is engraved with the year 1953. I know through my extensive family research that sometimes records can be wrong but I would like to know for certain as it will help me determine who her mother was. 

Thank you,

Jennifer