Name and date of marriage from “McCaul Family Scotland” (first compiled in 1991 and updated to 2002) by Marcia Barbara (Barbara) McCaul, Canada (b. 1932, d. 2002). Barbara was the great-great grandaughter of Gilbert McCaul (b. 1765) and Janet McFarlan (b. 1770). Brian of nzolivers.com is the great-great-great grandson of Gilbert and Janet.

Result from marriage search on New Zealand BDM website in March 2022:
1882/1133. Bride: Emma Bayly. Groom: Alfred Alexander Gower

Full date of marriage of 20 April 1882 confirmed from further searching in March 2022 on BDM Search by incrementally changing the date range for the marriage.

Children of Emma and Alfred found from birth search on New Zealand BDM website in March 2022:
1883/2447. Gower, Elenor May. Mother: Emma. Father: Alfred Alexander
1884/9554. Gower, Alfred Morrison. Mother: Emma. Father: Alfred Alexander
1886/1793. Gower, Arnold Arthur. Mother: Emma. Father: Alfred Alexander
1887/9596. Gower, Clarissa Alethea. Mother: Emma. Father: Alfred Alexander
1891/13530. Gower, Percival Fred. Mother: Emma. Father: Alfred Alexander

Date of death confirmed for Emma, place of burial in the Gower family plot, from Aramoho Cemetery records found in March 2022:
Block D row 2. 1651.
In loving memory of EMMA wife of Alfred A GOWER, died 20th December 1925 aged 68 yrs; also ALFRED ALEXANDER GOWER, died 13th November 1940 aged 83 yrs. [Emma would have been born circa 1857].
Block D row 2. 1652.
In loving memory of OSWALD KAY STEELE beloved husband of Eleanor May, died 5th July 1950 Elinor May - crem. Wellington, ashes bur 13 Apr 1965
Block D row 2. 1653. [First husband of daughter Elinor]
In loving memory of PERCIVAL FRED GOWER died 17th June 1951 [Son of Emma and Alfred]
Block D row 2 p57:
McCAUL Elinor May - crem. Wellington, ashes bur 13 Apr 1965 [Daughter of Emma and Alfred]

Year and country of birth from search on New Zealand BDM website in March 2022:
1856/2167. Bayly, Emma. Mother: Grace. Father: James

Full date of birth of 20 January 1856 from further searching in March 2022 on BDM Search by incrementally changing the date range for the birth.

Kim Cripps (wife of Douglas Cripps, with Douglas being a cousin of Brian of nzolivers) alerted me to a Facebook post of 22 December 2023 by parliamentary MP, Andrew Bayly. Andrew wrote, "The Bayly’s arrived in New Plymouth on the ship Amelia Thompson in 1841 and I grew up on a farm near Whanganui".
Now, the Olivers had arrived on the same ship.
However, of equal interest, Brian of nzolivers maternal step-grandmother was Elinor May Gower [Nellie]. Elinor’s mother was this Emma Bayly and her parent’s and older brother are listed on the Amelia Thompson Passenger List, along with two other Bayly familes:
1. James age 25 and Grace age 22 [Emma Bay’s parents] with son Arthur age 1 year
2. William age 30 and Elizabeth 26 with children Daniel 6, Ann 2, and Jane 11 months
3. Thomas Bayly age 36 and Susan Bayly age 35 with children Elizabeth 10, Thomas 8, William 6, Ann 4 and Issac 11 months.

Newspaper account of wedding between Alfred Alexander Gower and Emma Bayly, sourced from New Zealand ‘Papers Past’ website in January 2024:
Hawera & Normanby Star, 1 May 1882
News and Notes
The Waitara correspondent of the Taranaki News writes: - "A wedding took place here on Thursday, the 20th inst. The bride was Miss Emma Bayly, niece of Thomas Bayly, Esq., and the bridegroom Mr. Alfred A. Gower, of Patea. The bridesmaids were Miss C. Bayly, the bride's bister; Misses M. and N. Bayly, her cousins. The gentlemen were Mr. Gower, who gave the bride to his brother; Mr. F. Bayly, and others from Hawera. The Rev. H. H. Brown officiated. The happy couple left for their home at Patea by the 4 p.m. train, amidst a shower of rice. This is the first public wedding that has taken place at Waitara.