According to the 1860 Pennsylvania census, Catherine was born in 1855. Patrick also had two brothers listed on that census: William born abt 1853, and John W. born 1852. But the census information has been a hard clue to follow, e.g. in 1860, they are all listed as born in Pennsylvania, and in 1870, they were all born in Irleand.
I know that they all died in America. Catherine married John Roache in 1877. She died in 1926 in Tennessee. Her death record lists Patrick Lydon as father and Sarah Turner as mother.
As for William and John, no other traces of them after 1870 Pensylvania census. On the 1900 Pennsylvania census, Sarah lists that she had 7 children, 3 were still living. That would eb patrick, Catherine..and on other unknown.