Keith was born Nannie Keith Bean on 14 February 1876 in Dayton, Kentucky. She attended a private school in Cincinnati and later graduated from Vassar. She undertook post-graduate work at the Universities of Michigan, Arizona and Chicago and was eventually awarded an MA degree. She taught French at Albion College, later heading the department of English Literature.
In 1903 Keith married Ralph (Guy) Ransom and went with him to Paris, where he studied art for a few years. When Keith was 32 years old, her husband died of tuberculosis. In order to support her daughter, Julia, Keith took an intensive course in design and then became head of the interior decoration section of the Carson, Pirie, Scott department store in Chicago. In 1910 she married James Kehler, a former colleague from Albion College and now an advertising executive from New York. His death in 1923 was a great and lasting sorrow to her.
From 1918 to 1922 Keith was leader of the Liberal Religious Fellowship in Chicago and Chief Counsellor for the Home Beautiful Service. She was involved in Hull House settlement work, prison reform at Sing Sing, and fruit and chicken farm operations. Her work on Municipal Ownership was incorporated in a report of the Federal Bureau of Labour and Statistics. She published articles and lectured on psychology, comparative religions and interior decorating. Under such titles as 'The Divine Adventure--Why be Unhappy?' 'Psychology of Human Relations', 'Making the Most of Ourselves', 'Child Guidance', 'Is Universal Brotherhood Possible?', 'Life's Essential Purpose', 'What is Permanent?', 'Crime and its Remedy', 'A Journey of the Soul', 'Making Houses Homes', 'The Beautiful Necessity' and 'Interior Decorating'.['Presenting Keith Ransom-Kehler', p. 1]
Keith met 'Abdu'l-Baha in London on 13 September 1911; the exact circumstances of the meeting are unknown. It seems, however, Keith did not become a Baha'i until May 1921. She was elected to the Local Spiritual Assembly of Chicago and served as its secretary. A part of Chicago's elite society, Keith gave up her social life when she became a Baha'i, although she retained her sense of beauty and elegance. When she was in Iran in 1933 she impressed the young Zikrullah Khadem as 'the most stylish woman he had ever met'. (Barron Harper, Lights of Fortitude, p. 100)