How does this look?
Remember the 1878 marriage for John Collins. Reference was Dec 1878 Henley 3a 1056A
Searching the 1871 census for a Catherine born ca. 1847 Wargrave, the best match is:
Catherine S Treacher, sister in law, unm, 23, b. Wargrave at Gloucester st George with Edwin and Mary A Newson.
Searching the complete marriage index for Dec 1878 under the name Treacher, we have:
Catherine Sarah Treacher, Henley 3a 1056A
His first wife would have been Sarah Elizabeth Alleway, as there is a death as follows:
Sarah Elizabeth Collins age 37 June quarter 1878 Henley.