Born and raised in the village of Dunscore in the south of Scotland, Haining was the matron at a Church of Scotland school in Budapest from 1932 to 1944.
The Scottish Mission School had around 400 day and boarder pupils aged from six to 16 years old, a mixture of Jewish and Christian girls.
The Church of Scotland said she helped keep the children safe for more than four years after the war broke out in 1939.
Despite numerous offers to return home she stayed on, saying: “If these children need me in days of sunshine, how much more do they need me in days of darkness?”
She was arrested by German officers in April 1944 and taken to Auschwitz the following month.