My great-grandfather's sister was Catherine Kerruish. He was born 1852.
1861 Census
Lezayre, district 5 entry 51, Sandy Lane
John Kerruish, head, married, 37, sailor, Ramsey
Catherine, wife, married, 32, Ramsey
John, son, unmarried, 10, Lezayre
Thomas, son, 8 Lezayre
Catherine, daughter, 4 Lezayre
Jane Kneal, mother in law, widow, 73 Andreas

John Joseph Kerruish married Catherine Kneale 21 December 1850 at Lezayre

1851, Lezayre, district 1, entry 73, Sandy Road
John Kerruish, head married 26, sailor, Ramsey
Catherine, wife, married, 21 Ramsey

There may be a connection between your Catherine & mine. I would love to hear back from you should there be or not be a connection.
Pam Lloyd (nee Kerruish)