Ruth Ethel Mulliken was a missionary and teacher and served the South China Mission of the American Board of Commissioners for Foreign Missions. She went to China in 1910 and served her final years in Hong Kong. In all, she had contributed to over 30 years work in the field of education in South China.
In 1940, Ruth Mulliken was teaching at Pui Ying Middle School (likely at Bonham Road) and receiving a grant for salary and rent from the South China Mission of the Presbyterian Church. After the fall of of Hong Kong, she was interned at Stanley Camp and later repatriated to the United States in 1942.
Obituary/Memorial: https://www.findagrave.com/memorial/139190605/ruth-ethel-mulliken
Source
1. Directory of Protestant Missions in China: https://divinity-adhoc.library.yale.edu/directories/1918_Directory.pdf
2. Minutes of Mission Council 1939/40 & Annual and Special Meeting 1940: South China Mission 1940