First given name from birth search of son on New Zealand BDM website in May 2020:
1873/15566. Oliver, Charles. Mother: Sarah. Father: William Alfred

Maiden name, approximate year of birth, date and place of marriage, from marriage record found in May 2020:
Name: Sarah Miller
Gender: Female
Marriage Age: 21
Record Type: Marriage
Birth Date: abt 1844
Marriage Date: 16 Apr 1865
Marriage Place: St Dunstan and All Saints, Stepney, Tower Hamlets, England
Spouse: William Alfred Oliver
Register Type: Parish Register

Country of birth, year of death of “1923” from an online family history written by great-granddaughter Helen Oliver found in February 2021 at:
https://wordpress70995.wordpress.com

Helen Oliver also writes:
“William Alfred Oliver and wife Sarah (1844-1923 b. Sarah Miller, in England) came to New Zealand in 1865 on the “Wild Duck”.

Country of death, from death search on New Zealand BDM website in February 2021:
1923/7981. Oliver, Sarah, died age 78Y

Full date of death of 28 July 1923 from further searching in February 2021 on BDM Search by incrementally changing the date range for the death.