Shannons of Derry and Rivoli

Last year, I visited old Toumullin House, and Derry and Rivoli Houses in Ballingaddy West, where my grandmother lived between 1864 and 1888. She was Mary Josephine Stritch, daughter of Thomas Andrew Stritch and Margaret Mary (Shannon), married at Kilshanny in 1861. She was sent to school at Dee House in Chester, where her aunt, also Mary Josephine Stritch, was Mother Superior. Margaret's brother, James Shannon, inherited the family home, Derry House, where Margaret returned with the children when her husband died in 1873. Shortly after they moved to Rivoli. In !888 Margaret sailed to Melbourne with her two daughters.

James' widow, Maria, died in 1906,  leaving one unmarried daughter, Emily. An older daughter, Marie, is not mentioned, so I don't know if she had died.

Finding out these things has left more questions. I would like to find out how many children Patrick Shannon of Derry House (Margaret's father) had, when James Shannon died, and how many children he had. What became of Emily and Marie Shannon, and are there any surviving descendants?

Any light woukd be greatly appreciated.

Andrew Thom