Hi, kilmartin,
I am new to this forum, but I too am looking to information on William Trewartha who married an Elisabeth Hitchins on 2/12/1823, St. Clements, Cornwall.
My info. so far has them having the following children:
Mary Jane, chr. 20/4/1825, St. Gluvias; Martha chr. 7/9/1828, St. Blazey; Susannah chr. 7/9/1828, St. Blazey; Mary Anne chr. 7/9/1798, St. Blazey; William chr. 19/10/1831, St. Blazey; James chr. 22/7/1832, Tynardreath; Lavinia chr. 13/10/1833, St. Hilary. My info. also has Mary Jane (1825) having one child, William T. b. 9/9/1846, Cornwall, d. 24/12/1918, Moonta, South Australia, m. 25/12/1873, Moonta, Sarah Quintrell, b. 17/1/1853, Cornwall,d. 19/7/1910, Moonta, SA.
I am still in some doubt about this info. being my line, as other historians have my William T. (1846) associated with another line and his birth date being 1849.
However, the info. above might be of some help to you,
Regards JPSmith.