Myrtle was born on the 12 Jan 1899 at Balfour, Southland New Zealand and is the twin sister of Ella, so born second/third child to James and Christina.
She lived almost her entire life around Dunedin and in 1922, married William Robertson, at Gore in Southland. Their first child was born at Timaru, with most arriving at Dunedin.
| Child | Born | Married | Children | Died | Comments |
| Milton Charles | 1923 | 1945/ 1950 | 5 | 1997 | Gordon/ Kerr |
| Heather Agnes | 1924 | 1947 | 4 | 2011 | MacKenzie |
| Leola Isabel | 1927 | 1972 | – | 2003 | MacKenzie |
| Christina Margaret | 1928 | 1951/ -/ – | – | 2009 | Hellyer/ Renner/ Vuleta |
| William Alexander | 1930 | abt 1957 | 2 | 2005 | Churchill |
| Olive Myrtle | 1931 | 1953 | abt 6 | 2005 | Cain |
| Arnold James | 1933 | – | – | 1955 | – |
| Colin Desmond | 1938 | ? | 2? | 2001 | Johnstone |
Myrtle passed on the 11 September 1976 at Dunedin, Otago, New Zealand and is buried at Andersons Bay Cemetery, Dunedin, alongside her husband in Block 222, Plot 56.
Her husband, William, predeceased her in 1965.