I believe that my g-grandfather Samuel McWilliams was the father of a daughter (Mary) to a woman named Edith in 1880.
This was the year that Samuel McWilliams married Elizabeth Stevens and had five children, three of whom died in infancy. I found this info through stumbling across the Papers Past link at
http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&cl=search&d=EP19191018.2.4&srpos=1&e=-------10--1----2samuel+mcwilliams-- which was a marriage notice for Mary and which gave the correct family residential address in Wellington. Although Samuel was at the time still married to my g-grandmother Elizabeth, Mary was noted only as a daughter of Samuel. Tracing backwards through the BDM site, I found that Mary McWillliam (no 's') was born to Samuel McWilliam (no 's') and Edith in 1880.
In 1903 Mary McWilliams (with an 's') married Thomas Ingerton, and had three children, Violet May in 1904, Thomas John in 1906, and Frances Ivy Elizabeth in 1907. According to Papers Past, Thomas and Mary Ingerton divorced in 1915 after Mary left Thomas and took up with one Charles Toy, and in 1919 she married one Gee Lee under her maiden name of McWilliams. I lost track of her after that.
According to Papers Past Mary Ingerton was a very talented opera singer during the period 1910-1912. This ties back to a claim by my grandfather that his sister was a renowned opera singer, but I could never find evidence of his having a sister surviving past infancy. It now appears that Mary McWilliam (no 's') was grandfather William David McWilliams' HALF-sister! This is why I couldn't find her!
I would love to make contact with any Ingerton family members of this lineage if they are out there at all.
Cheers - Bugly
