I was able to find the forename of the Ronans' father and the surname of their mother on familysearch.org in the death records of two of their children. The information is as follows:
Name: Michael Ronan Death Date: 03 Jul 1909 Death Place: Lowell,,Massachusetts Gender: Male Race: White Death Age: Estimated Birth Year: Birth Date: Birthplace: Ireland Marital Status: Single Spouse: Father: Matthew Ronan Mother: Mary Dunnigan Film Number: 2313393 Digital Folder Number: 4283145 Image Number: 00254 Reference Number: 441 Collection: Massachusetts Deaths, 1841-1915
Name: Mary Ronan Welch Gender: Female Burial Date: Burial Place: Death Date: 30 Jun 1904 Death Place: Boston, Suffolk, Massachusetts Age: 62 Birth Date: 1842 Birthplace: Ireland Occupation: Race: White Marital Status: Married Spouse's Name: David Welch Father's Name: Matthew Ronan Father's Birthplace: Ireland Mother's Name: Margaret Donegan Mother's Birthplace: Ireland Indexing Project (Batch) Number: B07462-3 System Origin: Massachusetts-EASy Source Film Number: 2069338 Reference Number: v 13 cn 291 Collection: Massachusetts Deaths and Burials, 1795-1910
Here we have two more variable spellings of the Dunigan name.