What an intriguing family you have to look for
In relative terms, there is more info than you can poke a stick at, for the daughter Mary, including her own mystery to unravel (her husband changes names). This what I've unearthed thus far:
Mary Forbes Olivia LANDELLS.1835 BIRTH:Mary Forbes LANDELLS
Born 9 Feb 1835, Kingston, Surry, Jamaica
Father: George LANDELLS. Mother: Margaret LANDELS
1856 MARRIAGE : - 24th May 1856, Sandhurst, Victoria, Australia
At Sandhurst, on the 24th instant, by the Rev. T. Raston, Mr.
George Pearce Marrack, to Miss Mary Forbes Olivia,
second
daughter of the late Captain G. Landels, of Her Majesty's
22nd Regiment.http://nla.gov.au/nla.news-page90001951908: DEATHMary Forbes Olivia Landels MARRACK
Died 24 Oct 1908, San Francisco
Finda Grave:https://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=169155390&ref=acomHer Headstone - and her obituary name her husband as:
Richard Thornton MARRACK What has become of the husband named on the marriage and births of her children: George Pearce MARRACK?
Obituary: MARRACK— In this city, October, 24. 1908. Mary Landells Marrack. beloved mother of Gertrude, Ernestine, Edith, Augustus, Noel, Ethelwyn, Cecil and Reginald Marrack. a native of Kingston, Jamaica, aged 73 years. Friends are' respectfully invited to attend the funeral tomorrow (Monday). October 28, 1908, at 1:30 p. m. from the chapel of N. Gray & Co., 2196 Geary street corner of Devisadero. Interment privateOf the children in the Obituary :
(5) Australia Birth records: Gertrude, Edith, Noel, Ethelwyn, Cecil
(3) Haven't found: Augustus* , Reginald, Ernestine,
(1) Does not mention Melville, who died Australia 1924 - he would be the 9th.
Plus there was:
(1) Angeline born and died 1859
(1) Bertha born 1863
** Note: Have found reference that he was Augustus Edmond Marrack b 1871 - but the only one I see of this name, age 21 in 1892, says he was a Native of Nevada.
CENSUS 1900: At 339 Pierce, San Francisco. Head: Richard T MARRACK 68, b Apr 1832, marr 30 yrs to wife. B England, Bookeeper
Wife: Mary F MARRACK 63, b Feb 1837, birthed 11 children (9 are alive, 2 are dead), b England.
Dau: Edith E MARRACK 30, single, b Oct 1869, b Australia,
Dau: Ethel F MARRACK 23, single, b Mar 1877, b Australia, Book Keeper,
Son: Noel B MARRACK 19, single, b Sep 1880, b Australia, Stenographer
Servant: Saki OKI 17, single, b Jan 1883, b Japan, At School.
The MARRACKS: all immigrated 1882 to the US.BIRTHS of Children in Victoria, Australia - parents: George Pearce MARRACK and Mary Oliva Forbes LANDELLS (some small variations in spellings):
1857 BIRTH of Child: Melville Geo Segismund MARRACK
Born: Sandhurst, Victoria, Registered 1857
(He died 1924 in QLD, Australia)
1859 BIRTH of Child: Angeline MARRACK
Born: Sandhurst, Victoria, Registered 1859
(She died 1859)
1861 BIRTH of Child: Gertrude Amy Augusta MARRACK
Born: Sandhurst, Victoria. Registered 1861
1863 BIRTH of Child: Bertha MARRACK
Born: Sandhurst, Sandridge, Victoria. Registered 1863
1866 BIRTH Child: Edith MARRACK
Born: Sandhurst, Victoria. Registered 1866
1874 BIRTH of Child: Baptiste Wrlothsley Noel MARRACK
Born, Kangaroo Flat, Victoria. Registered 1874, Victoria
1876 BIRTH of Child: Florence Etheline MARRACK ( aka: Ethelwyn)
Born, Kangaroo Flat, Victoria. Registered 1876, Victoria
(She died 1951 in San Francisco, surname CARROLL)
1879 BIRTH of Child: Cecil Mortimer MARRACK
Born, Kangaroo Flat, Victoria Registered 1879, Victoria
It was her son Noel (ie: Baptiste Wurlthesley Noel MARRACK) I had found first:
1905: Appointment as a Letter Carrier for the US Government
Baptiste W. N. Marrack, born California
Residence Date: 1 Jul 1905
California, Voter Registrations1907: Baptiste W. N Marrack, age 32, at 3032 California, Letter Carrier
1908: Baptiste W. N Marrack, age 35, at 30681 California, Letter Carrier
1910: Baptist W. N Marrack, age 36, at 411A Lyon, Letter Carrier
1914, 1916: Baptiste W. Noel Marrack at 540 Baker, Letter Carrier.
1933: Baptiste W. N Marrack at 2084 Golden Gate Ave, Carrier.
1910: CENSUS - at 410 Lyon, San Francisco, CAHead: Baptiste W N Marrack, 36, single, Letter Carrier US Govt
Sister: Edith E MARRACK 40, single, no occupation
Sister: Gertrude MARRACK 45, single, Music Teacher, own account
All immigrated 1882.
All b Australia. Father: English, mother Jamaica1918: WW1 Registration , 12 Sep 1918, San Francisco.Baptiste Wurlthesley Noel MARRACK, age 45
Address: 540 Baker Street, San Francisco, California
DoB: 30 Sep 1873, Naturalized US Citizen
Occupation: Letter Carrier
Nearest Relative: Brother: Reginald B C MARRACK, of 1482 McAllister Street.
Description: Tall, Stout, Bald, Gray eyes.
Like I said, Stick, poke, it all falls out
A lot more to pursue if inclined!
Not in the least, the identity of the husband!
Cheers
AMBLY