From 1941 to 1950, Thresher was a member of the Newton School Committee.[2]
Thresher served in the Massachusetts House of Representatives as a Republican from 1951 to 1961.[1] In addition to serving on the education and public welfare committees, she was also the first woman to serve on the ways and means committee.[1] After her initial election in 1950, she was elected president of the freshman class, the first woman to hold that position.[1] Her priorities as a legislator included education and the elderly.[1]