Olga: siblings Olivia Beryl, John Arthur Douglas and Dorothy Mina.
I believe your father was James Richard Lloyd a solicitor in the Burton on Trent area?
You have a cousins in the UK through the John Arthur Douglas line.
Olga's parents: Andrew Reuben Hessing/ Daisy Grace Tulip ( she possibly came to the UK in May 1950 aboard the Maloja, and went to live at 2 Belvedere Rd Bridlington)
Andrew's parents: John Henry Hessing/Mary Ann Davis(2nd wife)
John Henry's parents: some question over whether Edward or Anthony Hessing (depending on which marriage papers you go by)/ mother unknown
Andrew Reuben is brother to my wife's grandfather Richard Arthur Hessing.
No known connection made yet to Col John Hessing of Agra.
Ancestry will be of little help. You either need to get the Church of the Latter Day Saints microfilms of the Three Presidencies in India to use locally or go to the India Office in London.
Col John had two sons that I know of: George and Thomas. John Henry's father (which ever it is) may be a descendant of either of these but again no proof. The timings fit and that is about all.