Looking for Brennan kin

My maternal great-grandparents each emigrated from Sligo in about 1887 to Boston, James Brennan, born 26 Sept 1859 in Agahanagh to Thomas Brennan and Mary McGowan,  and Mary Ellen Gunning born 12 May 1865 in Annaghgowan Parish to Thomas Gunning and Honoria Scanlan.  Married in Cambridge, MA, in July 1891.  A Thomas Brennan [born July 1858], Michael Brennan [born Dec 1867] boarded with the James Brennan family in Boston, accot-rding to the 1900 U. S. Census.

My wife and I visited Sligo in June 2008, including Ballinafad, the Agahanagh peninsula where the old cemetery remains as well as Ballindoon and the old abbey,  We found a few familiar names on stones in the two cemeteries, but little more. 

I am looking for information on and/or contact with descendants of other children on James Brennan and Mary McGowan.

Chuck Farmer

Fernandina Beach, FL