Thanks maddys52.  
I didn't have death date for Frances and this looks as though it could be right. No, I haven't found a second marriage date either.
As for the family, the 1841 census,  which includes William, has little info. other than names and genders. However, I filled in the birth years from the 1851 census, in which Frances jnr.is missing.
Thomas Wells  1807
Frances    "
Thomas    "      1834
Frances    "     
William    "       1838
George    "       1841
Somewhere I, too, found the family with second names quoted.  They're quite memorable. Don't remember why I discounted them. Where did your info come from? seventyplus