Yes, I have William Lewis on the 1841 census (fiche #17-023-023)
The only data I have on Hannah Owen is her daughter's (Elizabeth's) birth certificate. Elizabeth was born September 24, 1841 in Llangyfelach and died in the US (Pennsylvania) June 26 1895. I'm guessing Hannah was born between 1816 and 1820 or so.
Elizabeth married Joseph Rees November 12, 1861 at the parish church in Llangynwyd.