I have just found this post in March 2012.
I can add more information. My name is John Breen and my grandfather was Thomas Breen born in 1895. He was the son of Thomas Breen and Catherine Todd. While your post refers to 5 children from this union I am aware there were two additional children after Edmund - Bridget born in 1892 and Thomas born in 1895. Further Thomas Breen (the one born in 1855) died in 1898 aged 43 years. His wife Catherine Todd married again to a man called Coakley and I think had 2 further children Joe and Nell.
Therefore my grandfather Thomas was the brother of your great grandfather Edmund.
Thomas Breen (b1895)and his wife May, lived in the state of Victoria in Australia, in a town called Longwood, near Euroa, all of his life. His son John (b1923) is my father.
I am aware that his sister Mary Ellen married a man named Brodie and lived in the same area for the whole of her life.
Feel free to send any further questions about this section of the Breen family.