Margaret Tierney/Daniel Healy

I am looking for information on Margaret Tierney, b 11 Aug 1825 in Ireland.She married, in 1846 (in Ireland) Daniel Healy, b. 1822, Ireland.They came to the US in 1848, via New York.They went to Conneticut, staying 5-6 years, then to Mendota, Dakota County, Minnesota, in about 1854, and a year later settled on 160 acres in Washington Lake Township, Sibley County, Minnesota.They had at least 6 children.Both are buried in St. Peter's Catholic Church cemetery in Mendota.I do not know where in Ireland she is from, but am wondering if she is a sister to my g-grandfather, Thomas Tierney, b 1819 in Westport, Co Mayo.His parents are Felix (John Felix?) Tierney and Mary O'Malley.Thank you!