Looking for connections to Margaret Twohig (b. 1816) who married John Casey, then James Brew after John's death. John was from Co. Cork, am guessing so was Margaret.
Margaret Twohig had at least three children with John Casey, including Mathias Casey. She had at least one with James Brew, Hannah Brew.
Margaret Twohig died in East Longmeadow (next to Hampden) in 1896.