Yes, Catherine Smith nee Marsh was married to John Hancock on 13th March 1831. The couple appear to have had three children: Joseph born c.1832 (no definate records) , John born or at least baptised on 6th February 1834, who must have died young as he never appears again. Then there was Thirza born on 1st January 1836. I have recently corresponded with a genealogist on the Thirza/Thirra conundrum, he believes that they were one and the same person, the earlier baptism of Thirra on 7th January may have happened if the girl child was sickly and seemed unlikely to survive, hence a hasty Anglican baptism. She may have then rallied and was rebaptised (and the name corrected) ten days latter in a Primative Methodist baptism. This was, I am told, quite a common practice in Victorian times. Alternatively they may have been twin girls, but there are no further records of Thirra after this, so if such a girl existed she died young, though I have yet to find proof of this.
I too have read that E.J.'s father had contracted an earlier marriage, but I've never found any evidence of this. In the 1841 census, Edward and his younger brother George were still unmarried and living with their mother in Well Street, Hanley. A few days later their mother died from dropsy and a couple of weeks later on 2nd August 1841, Edward Smith married Catherine Hancock. On the certificate Edward said he was a bachelor and there is no reason to believe otherwise.
I'm still trying to get my head around many of the twists and turns in Smith's family history, but the facts stated above come from either local parish accounts or birth, death or marriage certificates in my possession. Hope this helps.