Irene May Blanchett was the daughter of Revd. Charles Isaac Blanchett and Ann (Annie) Walsh, C.M.S. missionaries based in South China. She was the younger sister to Hannah Gertrude Wittenbach (née Blanchett).
She was born about 1911/12 and appears to have been better known as Maysie Blanchett.
The book "Change and Continuity: A History of St. Stephen's Girls' College, Hong Kong, 1906-1996" by Kathleen E. Barker mentions "Maysie Blanchett, a young science graduate from London University, and the daughter of C.M.S. missionary, Revd C. I. Blanchett, whose sudden death in early 1933 shocked the Mission, was a member of the staff at St. Stephen's Girls' College from 1933 to 1940." In the spring term of 1940, she left the College and continued her teaching career at Belilios Public School.
After the fall of Hong Kong she was interned at Stanley Camp.
Sources
1. Obituary: https://www.ancestry.ca/genealogy/records/irene-may-blanchett-24-19pd8c2
2. https://www.chinafamilies.net/internees/7327-blanchett-irene-may/
3. Maysie Blanchett appears in the photo https://gwulo.com/media/45398
4. Maysie Blanchett's name/signature appears in red at bottom left of the "Day Joyce Sheet" held by the Imperial War Museum.
See: https://www.iwm.org.uk/collections/item/object/30083388. An explanation of the "Day Joyce Sheet" is given at: https://gwulo.com/media/46458
5. St. Stephen's Girls' College "News Echo" Magazine 1939/40. See Hong Kong Memory here