In 1940, she ran on the Republican ticket for an at-large seat in the United States House of Representatives but lost to the Democratic incumbent Caroline Love Goodwin O'Day.

Donlon was nominated by President Dwight D. Eisenhower on June 22, 1955, to a seat on the United States Customs Court vacated by Judge Genevieve R. Cline.

She was confirmed by the United States Senate on July 29, 1955, and received her commission on August 1, 1955.

In recognition for her generosity to Cornell and her service as trustee, a women's dormitory was named in her honor in 1961.

A Conference for college trustees and administrators regarding affirmative action for women in education was also named in her honor.