First two given names from birth search of son on New Zealand BDM website in June 2020:
1917/2560. Waswo, James Walter. Mother: Alice Olga. Father: William Henry

Year and country of marriage from search on New Zealand BDM website in June 2020:
1912/7793. Bride: Alice Olga Sutton. Groom: William Henry Waswo

Maiden name, full date of marriage of 31 July 1912 from further searching in June 2020 on BDM Search by incrementally changing the date range for the marriage.

Children born to William and Alice as found from birth search on New Zealand BDM website in June 2020:
1914/28393. Waswo, Margaretta Elizabeth. Mother: Alice Olga. Father: William Henry
1916/7303. Waswo, Harry. Mother: Alice. Father: William Henry
1917/2560. Waswo, James Walter. Mother: Alice Olga. Father: William Henry [Married Irene Maud ANDREWS]
1919/3061. Waswo, Betty Louisa. Mother: Alice Olga. Father: William Henry
1920/10396. Waswo, Norman William. Mother: Alice Olga. Father: William Henry