Well, that’s just confusing. I thought Sarah might be John’s sister.
It looks as though the son informant gave the name Hugh instead of Michael. The mother’s name looks correct.
In 1881 your family are living at 7 Black Bull Close.In the same census at 9 Black Bull Close, you have the Watson family.Robert Watson and Susan b Port Glasgow (not sure this is correct).There is a boarder, Sarah McCrorey b Port Glasgow too. Marriage 1870 Robert Watson and Susanna McRoryhttps://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1870/11389/8181636.pdfFather is Michael and residence Grogan.There is a baptism 28th February, Drumaul parish (transcribed as Merory) Susan and Margt Night. Also19th September 1852Sarah McRory with parents Michael and Margaret McNight.You can access these on catholic NLI site - Drumaul parish as earlier posts.Scottish records might show more to see if all this relates to your family.
I searched for McCrorys in Port Glasgow and found Sarah. I had already found your family earlier and recognised the address the census.Then lots of searching/confirmation of Catholic records etc.