Thank you so much for all of the very helpful responses.
I had another thought about the name of Matilda’s father, could she have been lying about it because she was a Protestant and was marrying a Catholic? I had this scenario in my own family and the couple left Ireland.
To summarise what I have so far is: At her marriage Matilda declared her father to be James Stevenson, a policeman. In a newspaper record of the wedding, Matilda’s father is names as Isaac Stevenson, deceased. At Matilda’s burial, her daughter declared Matilda’s father to be Robert Stevenson.
There is one further confusion, a Matilda Stevenson born in 1881 is the daughter of William Stevenson who was a policeman but the birth was in Kilkenny and looking at the family history, I think I can discount that possibility.