Re the 1939 Register
Harriet Turner in Rye may not be the right one

She is living with James E Cleland born 1904 and Constance Y Cleland born 1907 (her surname later changed to Jacoby)
Plus a son of James and Constance.
Constance seems to have married as Jacoby in Pancras in 1932 - spouse James E Cleland.
Her birth reg
JACOBY, CONSTANCE YVONNE
Mother's Maiden Surname:
TURNER GRO Reference: 1907 S Quarter in EDMONTON Volume 03A Page 651
Marriage in Edmonton district in Sep qtr 1901
Arthur Martin Jacoby
+
Caroline Constance Turner
The Jacoby family are in Prittlewell, Essex, in 1911
https://www.familysearch.org/ark:/61903/1:1:XWN3-SLGCaroline Jacoby seems to be in Napsbury Hospital in 1939
Her death
JACOBY, CAROLINE CONSTANCE
Age at Death (in years): 76
GRO Reference: 1954 M Quarter in ST. ALBANS Volume 04B Page 192
There may be a mix up with the ages in 1881 in Hornsey
Was Caroline's mother Harriet Turner?
https://www.familysearch.org/ark:/61903/1:1:Q27Z-6MDZon ancestry
https://www.ancestry.co.uk/discoveryui-content/view/15832546:7572Struggling with a birth for her.
So was she illegitimate? Where might Buston come into things?
BUSTON, CAROLINE CONSTANCE
Mother's Maiden Surname:
— GRO Reference: 1878 D Quarter in EDMONTON Volume 03A Page 219
also
BUSTON, WALTER WILLIAM
Mother's Maiden Surname:
— GRO Reference: 1874 M Quarter in EDMONTON Volume 03A Page 186