Mary Gaffney Lynch, Cootehall Parish, County Roscommon

Mary Gaffney Lynch, b. 1803 (estimated) from Cootehall Parish, County Roscommon, married to John (or possibly Thomas) Lynch and immigrated to Stalybridge, England with her children and their families-Thomas, John, Katherine Lynch and Betsy (Bessie). Per the US 1870 census, she resided in Lawrence, Essex County, Massachusetts, USA and was 68 years old. I have been unable to locate her after the 1870 census despite extensive research in Massachusetts. Any information would be greatly appreciated