This is as far back as I've been able to get with my side of the line, so if you have any info pre-1847 about the family it'd be much appreciated.
I can tell you that James McIlrath married Sarah Ann Urrie, and emigrated to Kiata, Victoria, Australia as farmers. They had a daughter Sarah Elizabeth McIthrath on August 9, 1879.
Sarah Elizabeth married my Great Grandfather, George Albert James on March 30, 1910, and had a son, David Keith in 1912, and Percival George (My Grandfather) in 1917. They lived primarily in Wagga Wagga, NSW.
P.G. James married Constance Forster in Melbourne Victoria in 1941, had 3 children - a son and 2 daughters, 6 grandchildren and 11 great grandchildren (with one more on the way). He died in 2005.