Winnie Agnes Burr Stewart was born on November 26, 1900 in Leoti, Kansas. She attended Wichita County High School and received a B.A. from Park College in 1921. Prior to her appointment as a missionary in December of 1927, Winnie Agnes Burr Stewart taught mathematics at Girard High School in Girard, Kansas, and Crawford County Community High School in Cottonwood Falls, Kansas. She taught mathematics, civics, hygiene, and bible at the Kohala Girls School in Kohala, Hawaii and then English at the Mid-Pacific Institute Grammar School, Honolulu, Hawaii.
Winnie Agnes Burr Stewart sailed for Siam in the summer of 1928, having prepared the previous year at The Biblical Seminary in New York City. From her arrival until 1932, she acted as principal of a girls school in Pitsanuloke, then spending the next eight years as a teacher at the Dara Academy for girls. March 28, 1941, Winnie married the Rev. Herbert W. Stewart. She then became principal at the Ranghsee Kasem School for girls in Nan, Thailand.
From 1942-43 and 1945-46, Winnie taught at the Dehra Dunn Girls' High School in Dehra Dunn, India, finally returning to Nan, Thailand in 1946 to once again be principal at the Ranghsee Kasem School for Girls until 1949. The Stewart's worked in Nan until 1953, when they returned to the United States on furlough for health reasons. Both then retired in 1957. Winnie Agnes Burr Stewart was reappointed in 1963 on a special term of three years and assigned to Dara Academy, finally retiring in 1966 to Wooster, Ohio.