First name, surname, year of death, had three children (no names), from Muriel Leo’s (nee Oliver, 1917-1998) Family Tree.

Second name of Elizabeth from Matthew Cox in an email dated 24 June 2015. Matthew is the grandson of Grace Elizabeth MCKOY.

Matthew writes in a 3 June 2018 email that, William and Grace had four children: Raymond Charles, Hilton, Hazel and Brian William.

Year of birth (circa 1887), year/country of death, from official Death Records search on New Zealand BDM website in June 2018:
d. 1965/40724, Cox, Grace Elizabeth, 78Y [Therefore born ca 1887]

Full date and place of birth, full date and place of death, place of burial, year of marriage, from:
https://www.findagrave.com/memorial/137454961/grace-elizabeth-cox

Year and country of marriage from search on New Zealand BDM website in January 2019:
1909/4844. Bride: Grace Elizabeth McKoy. Groom: William Charles Cox

Full date of marriage of 9 December 1909 from further searching in January 2019 on BDM Search by incrementally changing the date range for the marriage.

Headstone photo, from in January 2019:
https://www.findagrave.com/memorial/137454961/grace-elizabeth-cox