Thomas Trevithick had three wives; the first Elizabeth Randal CANDY was born in 1832 in Truro, Cornwall, England and married Thomas in 1853 in Plymouth before they sailed to Australia. After having at least 7 children while Thomas worked gold fields in NSW and Victoria (her death certificate states 10), she died in Sydney in 1871 aged 39.
Thomas' second wife was Margaret Hosier, a widower, who he married in his home at Hill End, NSW on 10 Sep 1881.
While I have not traced her origins, the Hill End Family History Register records the marriage as:
10 Sep 1881 St Andrews Hill End
Spouse Margaret Hosier (widow nee Pigram)
B Bishop Stortord ENG
D 12 Apr 1892 Hill End
Parents: Joseph Pigram*
Thomas' third wife was Mary Ann GREEN. When they married on 14 Mar 1900 he was 66 and she was 28. Mary Ann had been born in Sofala NSW to Thomas GREEN and Rosanna nee BRYSON. Five years before they married, in 1895, she had given birth to an illegitimate child Winnifred GREEN:
NSW Reg: 23030/1895
Name: GREEN, WINNIFRED M
Father: Not named
Mother: MARY A
District: HILL END
Thomas died in 1913, and the year before he died he transferred his home to Mary Ann Green. She seems to have lived at their home in Hill End till 1936 when the title was transferred.
Mary Ann Trevithick nee Green died on 8 Jan 1949, and is buried at Rylestone Cemetery NSW:
I'd had less luck tracking the fate of Winifred, Thomas' step-daughter, but now think I've found her. Of the few Winifred (various spelling) Green's, this marriage was present in nearby Bathurst:
NSW marriage Reg: 3860/1916
Husband: CARL, HENRY
Wife: GREEN, WINIFRED M
Sure enough, her death is register with correct parentage:
NSW Death Reg: 7608/1957
Name: CARL, WINIFRED MAY
Father: Not listed
Mother: MARY ANN
While no children have yet been traced, I'm still investigating. It's nice to trace Thomas' step-daughter.