Martin Sheehy and Margaret Donoghue Sheehy

My great great grandaunt was Margaret Donoghue,born about 1838 in Drommartin, Rattoo. She was the daughter of Jeremiah Donoghue and Mary Sullivan. In 1861, she married Martin Sheehy; the marriage is recorded in Causeway.Together they had the following children: John(1862), James(1864), Mary(1866) Anne( could be Johanna)(1868), Patrick (1870), Jeremiah(1872) and Ellen(1874). Martin died in 1878, Margaret died in 1876, Jeremiah died in1882 and Ellen in 1877. I'm looking to determine what happened to the surviving children?

I believe that John married Johanna Brosnan and they had the following children: Martin, Mary, Patrick(1890-1890) and James(1890) I'm wondering about the surviving children as well. At he time of the birth of Patrick and James, their father John was living in Boston according to birth records on irishgenealogy.

Here is what I think that I know: The marriage of Martin and Margaret was performed at the Chapel in Causeway in 1861. The witness was my great great grandfather James Donoghue. Margaret died in 1876; the informant was her husband. Martin died in 1878; the information was my great great grandfather James. 

The marriage of John Sheehy and Johanna Brosnan,was also performed at the Chapel in Causeway in 1887. The witnesses were James and Jerry Donoghue. Johanna was listed as a widow in the 1901 census living with her 3 surviving in children In the 1911 census she was listed as married with no reference to the whereabous of her husand John; she was living with her father Patrick, brother Edmond and her 3 surviving children. A final reference to Johanna was that she was listed as the informant  in 1916 when her father died. 

So in essence, John Sheehy was in Boston in 1890 and either died there or continued living there after that time. He may have still been living after 1911 depending upon which census you believe. James Sheehy, brother to John was alive in 1877 to report the death of his sister Ellen I have no clue as to what happened to him after 1877 nor to his sister Mary, sister Johanna nor brother Patrick. 

John Sheehy's family is also a mystery including when and where he died, where hsi wife died and the fate of his children, Martin, Mary and James. They MAY have immigrated; I can find no records on the irish genealogy site relative to marriages or deaths for any of them. I can use a second or third opinion as to what happened to these folks.