I'm sorry I have little info re: Timothy Brosnan's wife, Mary Shea. My great-grandfather (their son, Michael) died when my grandmother (Mary Brosnan-see earlier emails) was six months old.
I have found in my research that the Gallivans/Galvins were always in proximity to other folks with similar/same names and origins. There are a large number of Galvins in and around Aglish, Banoge and Anascaul County Kerry.
In researching my great-grandmother, Catherine Galvin Brosnan Foley's, immigration, I found her sisters and brothers in close proximity as well as other extended family members like the Deanes and Flahives.