You have solved the Mary mystery I think, ‘tho in a round- about way. I have Mary born 1855 reg. V18558253 45C/1855. This must be Elizabeth. You have her marrying a George T Brown in 1866. She would have been 11 years old! I did a search of NSW birth/Death registry and found an Elizabeth Wenban married a George T Brown in 1886 and found 3 children, an unnamed child born 1887, Louis born 1890 and Gordon W born 1894. All three children have parents listed as George T. Brown and Elizabeth. I dug deeper. Catherine is not listed as mother in any of the death notices for Elizabeth Brown, so it was difficult and confusing. I found a death for Elizabeth Brown, father William, died at age 62 in Murrumburrah in 1917. That would mean she was born in 1855. Another Elizabeth Brown died in 1899 in Sydney no name given for mother, but father given as William.Either of these fit the given information. There are also two Elizabeth Browns listed as dying at Newtown,but neither fit the profile. One died in 1990, mother listed as unknown,(the one I think you found, but as Elizabeth gave birth to another child in 1894, this can't be Elizabeth Wenban) and one in 1897, but had Elizabeth as the mother, not Catherine. Without any further information, it is a toss up. My money’s on the one who died in 1917. The third child was born in Tamworth, which suggests the family may have relocated to country 1890-1894.
I have another Mary Wenban, child of William and Catherine Wenban, born in 1864 Reg, V1864970 52/1864. She married William H Pearce in 1887, reg 406/1887, two children William R L born in 1887 reg. 19938/1887 born Liverpool, and Vera 19698/1890 born Liverpool, in 1890-d.1891. Mary died 1890, Liverpool death reg. 7464/1890, possibly as a consequence of Vera’s birth, and baby Vera didn’t survive long after her birth.
Tryphena and Tryphosa are listed in NSW death registry, spelt as Trephena V1853902 106/1853 and Trephosa, V18532869 102/1853 children of Catherine and William Wenban. Daughter Catherine’s death is also listed in same year, V18532782 102/1853.
I was thinking about comments both Peter and Myles have made about learning more about the lives of our forebears beyond birth/marriage/death dates etc. I agree that it adds so much more to family history to know something of the sacrifices and struggles they had in an effort, not only to create a better lives for themselves, but for their children and children's children.Each thread we manage to gather, adds colour and dimension to the tapestry of the life of our own families, and we each add to the fabric as time goes on.
As we grow old enough to recognise our own mortality, we seem to understand this better. Thank you for your help,