Bourke and Meagher of Knockshearoon

My ancestors James Meagher/Maher ("of Drombane") and Margaret Bourke ("of Knockshearoon") were married in 1819; their marriage record is recorded in the RC records of Borrisoleigh. They had one son, Thomas, baptized in Borrisoleigh parish in 1819, and several other children (including Michael, Cornelius, John, Ellen, Margaret and Bridget) baptized in and after 1829 in Upperchurch parish.

Margaret Bourke may have been the daughter of Mary Bourke, widow, recorded in the 1832 Tithe Applotment Book for Glenkeen civil parish as having a small tenancy in Knockshearoon. Mary is no longer listed by the 1851 Griffith's valuation, but a Cornelius Meagher (perhaps her grandson?) is. This Cornelius Meagher is said to have left for Quebec in 1851.

Most (if not all) of the children of James Meagher and Margaret Bourke are found in the United States by 1860. It appears the children first went to Canada (Montreal?) toward the end of the famine years (say between 1848 and 1851), then to New York, then back to Canada. Many of them ended up in Melrose, Minnesota, by 1860 or soon thereafter.

I'm interested in contacting others who might be researching this or other Bourke families of Borrisoleigh. It would be wonderful to identify the husband of the widow Mary Bourke or connect Margaret with her, or even to connect to the family of Walter Bourke of Borrisoleigh (17th century). I suspect there must be a connection, but I doubt that it can be traced now.