Edit: OK I found her at last
Her birth was registered as Hilda Eleanor Blanch Hardings in Q3 1884 Marylebone, London.
"England and Wales Birth Registration Index, 1837-2008," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:2XLR-K61 : 1 October 2014), Hilda Eleanor B Hardings, 1884; from "England & Wales Births, 1837-2006," database, findmypast (http://www.findmypast.com : 2012); citing Birth Registration, Marylebone, London, England, citing General Register Office, Southport, England
Her immigration record under the surname Leleu has a birth year of 1884 so the 1911 census age is incorrect.
Her parents are proving tricky to find although her mother's maiden name was Jackson. This is probably Hilda with her widowed mother in the 1891 census:
"England and Wales Census, 1891," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:35ZQ-B6Z : 2 May 2019), Hilda Harding in household of Mary Harding, Marylebone, London, England, United Kingdom; from "1891 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO RG 12, London county, subdistrict, The National Archives of the UK, Kew, Surrey
“Charles John Newhill Leleu was born at Babbacombe, Devon, on 6 June 1912, the son of John Charles Leleu, a solicitor, and Hilda Blanche Harding, the daughter of Judge Harding of Shanghai. After World War I, during which JC Leleu was decorated for bravery, the family came to Australia and then to Fiji."
https://blackdiamondheritagecentrebulli.wordpress.com/illawarra-remembers-1939-1945-wwii/military-awards-in-ww2/illawarra-obe-awards-in-ww2/
I've no idea whether Judge is a name or title. Hilda's modest background would seem to rule out a judge but perhaps someone can resolve it.
Just to prevent other people wasting time (like I did) there is a different Hilda Blanche Harding born to parents Edmund Francis Harding and Rosina Emily Chowne on 17 July 1887 in Dalston, Hackney, London.
She attended Christ's Hospital school and later returned there as a teacher. She appears on the 1911 census in St Helier, Jersey as a teacher so she is definitely not the same Hilda who was working at the Torbay Hotel in 1911 as given by Marion Poole. I note the managing director of the hotel has the same surname as the questioner (!) so this is definitely the Hilda she's interested in.
