Hi Gem,
You certainly seem to have a problem. Since I'm at a dead end with my own research at the moment; I thought I'd try to help. Well here goes:
PATRICK and ANN SHERRY had (at least) the children
WILLIAM, BRIDGET and ANN.
The youngest ANN married WILLIAM BAMBER in 1845 (Wigan reference ROW/3/11)
They had (at least) the children JANE (b. abt. 1845), CATHERINE (b. 1847) and JAMES (b. 1858). They also probably had a son called WILLIAM who died at the age of 12 days on 9th October 1860 and most likely a daughter called MARY ANN, b. 1864. One could assume because of the big age difference that Catherine and Jane could be the children of a first marriage, but there is no evidence of this. Ann and William were already married in 1845. I suspect they lost several children, like most other people at that time. The family are hard to find in 1851. Catherine was, of course, staying with her grandparents SHERRRY, and there was a Jane of the right age staying with a grandmother BAMBER in Blackburn. However, I don't know whether she is the correct Jane as she supposedly was not born in Wigan.
In 1861, the family is together with grandma SHERRY and Bridget's daughter CATHERINE LOWE.
However, there is also another Catherine Bamber aged 8, born abt 1853, in this census. She is the daughter of JAMES BAMBER, 40, and ELLEN BAMBER, 38. She has three sisters, Mary, 16, Ann, 10, and Abigail, 2.
It seems to me that these two CATHERINE BAMBERS married in 1874 and 1879 respectively:
CATHERINE BAMBER married WILLIAM COX in 1874 (ROW/37/191), which indicates a RC marriage where the registrar was present. William Bamber was CofE, but Ann Sherry was an Irish Catholic, who would presumably have wanted the children baptised as Catholics.
The other CATHERINE BAMBER married JOHN SHERLIKER in 1879 (C11/4/26). This was a Church of England marriage.
If I were guessing, I'd say you need the other Catherine and not the one with the Sherry ancestry. But perhaps I am wrong. Have you bought this marriage certificate?
The COXes are easy to find in the 1881 census, They have John, 12, who was probably from a first marriage, William,6, Joseph,4, and Ellen, 6. The name Ellen makes me hesitate a little as the mother of the CATHERINE BAMBER, b. 1853 was Ellen. It was usual to call one of the daughters after the grandmother.
I can't find the SHERLIKERs (and all kinds of variations of the name) at all. In Preston in the 1881 census, in St Peter's district, there is a John Sherliker, aged 45, who is married but living alone as a boarder, but he seems to work in a cotton factory. There's also an Alice Sherlicer, 35, which would be the correct age. She's a cotton weaver (weren't they all?) and is also living alone although married, in the same district. This Alice seems to have died aged 56 in 1914, which would place her birth at the time of CATHERINE BAMBER nee SHERRY. There is the possibility that her name was CATHERINE ALICE and that in later life she preferred to be called Alice. I know this seems far-fetched, but it did actually happen. No Catherine Sherliker died in Lancashire in the 100 years folllowing Catherine Bamber's birth. There was also no marriage of a Sherlicker to a Hickman. I couldn't find the birth of Nellie in 1883, but it obviously happened if you have the birth cerificate. Could she have possibly been John's illegitimate daughter with Catherine Hickman? Illegitimate children certainly weren't unusual in those days among the lower classes.
You can't find the BAMBERs after 1861 because (1) William Bamber died on 16th December 1869 and (2) Ann was probably listed as Sherry and not Bamber. In 1871, she seems to have been living with her brother JAMES (another candidate as a child of Patrick and Ann Sherry, together with Owen and a couple of others that I can't yet prove) and child MARY ANN BAMBER, aged 7. James probably told the censor Ann was his sister and so he wrote down Sherry. At any rate, ANN BAMBER died at the same address (Patrick's Row, Wigan Lane) on 9th July 1880 and so did not appear in any more censuses.
That's all I can tell you at the moment. What were the names of the SHERLIKER/BAMBER children? I'm often messing about on ancestry and other sites and would keep things in mind.
Good luck with your search!
LEP