| Name | Birth date | Relationship with Michael McGrath |
|---|
| Nora | Abt. 1814 | 3rd great-grandmother |
| Nora | 7/25/1886 | Great-grandmother |
| O'Brien, Another Child | | 2nd great-grandaunt/uncle |
| O'Brien, Beatrice | | 1st cousin 3 times removed |
| O'Brien, Cathrine (kate) | Abt. 1/1855 | 2nd great-grandaunt |
| O'Brien, Colleen Ann | | Wife of the 3rd cousin once removed |
| O'Brien, Dennis | | 3rd great-granduncle |
| O'Brien, James | | 1st cousin 3 times removed |
| O'Brien, James | Abt. 1824 | 3rd great-grandfather |
| O'Brien, James | 7/15/1856 | 2nd great-granduncle |
| O'Brien, John | | 4th great-grandfather |
| O'Brien, John | | 3rd great-granduncle |
| O'Brien, John | Abt. 1851 | 2nd great-granduncle |
| O'Brien, Kids | | 2nd cousin twice removed |
| O'Brien, Margaret | | 2nd great-grandaunt |
| O'Brien, Mary | | 3rd great-grandaunt |
| O'Brien, Michael | | 3rd great-granduncle |
| O'Brien, Michael | Abt. 1858 | 2nd great-granduncle |
| O'Brien, Michael J. | | 2nd great-granduncle |
| O'Brien, Nancy | | 3rd great-grandaunt |
| O'Brien, Sarah | 1851 | 2nd great-grandmother |
| O'Brien, Son | | 2nd great-granduncle |
| O'Donnell, Baby | 2/27/1979 | 3rd cousin |
| O'Donnell, Cheryl | 3/1/1963 | 3rd cousin |
| O'Donnell, Cindy | 4/1/1964 | 3rd cousin |
| O'Donnell, Connie | Unknown | 2nd cousin once removed |
| O'Donnell, Deanna | 6/29/1938 | 2nd cousin once removed |
| O'Donnell, Francis Vincent | 6/7/1907 | 1st cousin twice removed |
| O'Donnell, James Michael | 3/21/1868 | Husband of the great-grandaunt |
| O'Donnell, James Vincent | 1/18/1911 | 1st cousin twice removed |
| O'Donnell, Jamie | 8/22/1966 | 3rd cousin |
| O'Donnell, Larry | 3/26/1941 | 2nd cousin once removed |
| O'Donnell, Lisa | 11/11/1970 | 3rd cousin |
| O'Donnell, Margret Aileen | 3/3/1915 | 1st cousin twice removed |
| O'Donnell, Mary Kathleen | 7/2/1905 | 1st cousin twice removed |
| O'Donnell, Nora Josephine | 3/28/1909 | 1st cousin twice removed |
| O'Donnell, Paul | 9/18/1948 | 2nd cousin once removed |
| O'Donnell, Reginald Eugene | 11/26/1912 | 1st cousin twice removed |
| O'Donnell, Sally | 8/23/1945 | 2nd cousin once removed |
| O'Mara, Ann | 12/25/1825 | 3rd great-grandmother |
| O'Mara, Catherine | | 4th great-grandmother |
| Opersteny, ? | | Husband of the great-grandaunt |
| Opersteny, Adolph | | 1st cousin twice removed |
| Opersteny, Francis | | 1st cousin twice removed |
| Opersteny, Frank | | 1st cousin twice removed |
| Opersteny, Joe | | 1st cousin twice removed |
| Opersteny, Josephine | | 1st cousin twice removed |
| Opersteny, Louis | | 1st cousin twice removed |
| Opersteny, Mary | | 1st cousin twice removed |
| Opersteny, Victoria | | 1st cousin twice removed |
