This family is already in England by the time of the 1851 Census, written and indexed as McFarlan, but it is the right group. Daughter, Mary, is aged 4, and son, James, is aged 10 months, both born in Co. Durham. Living with them are Bernard and James McCann, both lodgers, born in Ireland.
By 1891, Susan Sr. is a widow, and she is living with her brother, Bernard McCann. Interestingly:
1891 English Census
McParlin, Owen, Head, aged 61, ??? dresser, born Co. Armagh, Ireland
McParlin, Ellen, Wife, aged 60, born Co. Durham
McParlin, Susan, Daughter, aged 25, born Liverpool
McParlin, Jas. Hy., Son, aged 21, hairdresser, born Liverpool
McParlin, Owen, Son, aged 19, bookbinder, born Liverpool
McParlin, Joey E., Son, aged 16, lithographer, born Liverpool
Very similar, but different, but another possibility for your Susan?
Where were John Henry & Susan married?