Thanks Dave, I have found that marriage now and it is probably the correct one, need to see if I can now find more children of the marriage to John and sarah to see if they are with relatives which will prove if we are correct.ie Harrison.
must recheck 1841 census because if William is first it is even more of a good match.
I think the census of 1841 I found showing John Hudson and Sarah is wrong, the last person on the census is a Joseph Hudson aged 1. looking on the census it says the maiden name of the mother is Pinder but as yet I have not found a marriage of a John Hudson to a Sarah Pinder.
I did though find a William Hudson (1833) living with the harrison family in 1841 and The Howe family in 1851 ( a Harrison married a Howe by the looks of it) and in 1861 that William Hudson is with Ann and a daughter Sarah A aged 3. William was born in the Crosspool area.
I therefore wonder if both his parents had died hence the reason he wa with relatives.
Do you think now I am on the correct track? Need to find another John and Sarah Hudson on the 1841 census or burial index.