Frederick Hibbert

[Kezzza]

On both censuses it states that his father is Thomas Hibbert and mother Mary Hibbert nee Riley.

Relationships on the census are how they are related to the head of the household, ie Thomas

Do you have the marriage certificate to Mary

I have someone sending a copy over when they find it, however I think it may says widower which is where people have Mary Jane Stephenson. But I am just guessing

I have received a copy -
Married 24 Oct 1868 Parish Church Drolysden, Lancashire, England
Thomas Hibbert 22 Widower Father Nathaniel (b. abt 1846)
Mary Riley 20 Spinster (b. abt 1848)

[Kezzza]

So, if Frederick is the son of Mary Jane Stephenson and Thomas Hibbert, one could assume that he was born out of wedlock as they did not get married until 24 December 1866, unless he was born between then and the new year, which is possible, therefore his birth would be registered in 1867.

[Milliepede]

If the Frances baptism you found 21 July 1867 was theirs then there wouldn't have been time for her to have had another child after Frederick (if he was born after they married I mean)