A few more snippets to add to the family tree which you may not have?

Death of the mother of Sydney ROWE [1933]………
https://paperspast.natlib.govt.nz/newspapers/AS19331205.2.4?query=harriett%20martha%20rowe&start_date=01-01-1896&end_date=31-12-1950&snippet=trueDeath of the father of Sydney ROWE [1934]……
https://paperspast.natlib.govt.nz/newspapers/AS19340829.2.3?query=harriett%20martha%20rowe&start_date=01-01-1933&end_date=31-12-1950&snippet=trueCemetery records:
ROWE, WILLIAM JOHNDetails M: Died 29-08-1934: Aged 68:
Place Hillsborough
Location Area 4 Block P Lot No 70
Remarks transcribed inscription reads " In loving memory of Harriett Martha dearly beloved wife of Wiliam John Rowe died 2 Dec 1933 aged 65 yrs Also William John dearly beloved husband of the late Harriett Martha Rowe died 29 Aug 1934 aged 69 yrs" Note different age at death
Information
Officiating
NZSG map
Trans number
________________________________________
Name
ROWE, WILLIAM JOHNDetails M: Died 29-08-1934: Aged 68: Cause of death - carcinoma rectum: Date of burial - 30 Aug 1934
Place Hillsborough
Location Area 4 Block P Lot No 70
Remarks Headstone: Yes
Information Occuptation - retired: Residence - 243 Ponsonby Rd, Auckland: Friendly Road:
Native place - Cornwall, England: Last from Cornwall: Years in NZ - 58Officiating Officiating Clergy - Rev Scrimgeour: Informant - Cameron & Bartlett
NZSG map A4 R10
Trans number 1459
ROWE, HARRIETT MARTHADetails F: Died 02-12-1933: Aged 65:
Place Hillsborough
Location Area 4 Block P Lot No 70
Remarks transcribed inscription reads " In loving memory of Harriett Martha dearly beloved wife of Wiliam John Rowe died 2 Dec 1933 aged 65 yrs Also William John dearly beloved husband of the late Harriett Martha Rowe died 29 Aug 1934 aged 69 yrs"
Information
Officiating
NZSG map
Trans number
________________________________________
Name
ROWE, HARRIETT MARTHADetails F: Died 02-12-1933: Aged 65: Cause of death - cerebral haemorhage: Date of burial - 4 Dec 1933
Place Hillsborough
Location Area 4 Block P Lot No 70
Remarks
Corrections - MI has HARRIETT not HARRIET: Headstone: Yes
Information Occuptation - married: Residence - 243 Ponsonby Rd: Bretheren: Native place - NZ: Last from NZ: Years in NZ - 65
Officiating Officiating Clergy - Mr James White & householders: Informant - J B Cameron
NZSG map A4 R10
Trans number 1459
Marriage:
1887/1008
Harriet Martha Ripley William John RoweBirth registration for Harriet Martha not found
PatsyAnn from the information provided I think you have details of the siblings of Sydney Rowe?
[Transcription/spelling errors shown above are not mine!!]
Minniehaha.