In 1954, Mendenhall accepted a position at East Carolina as Director of the Student Union. In this role, she developed the college union to match the growth of the school. Her initiatives included establishing bridge and chess clubs, a freshman orientation program, assistance programs for transfer students, and established a scholarship program. She is also credited with helping popularize art shows and the watermelon festival on campus.
An avid musician, Mendenhall performed in a number of choirs and was a popular soloist for weddings. She loved the outdoors and spent her free time hiking, golfing, and playing tennis. In 1971, she joined a conservation group that visited multiple countries in eastern Africa.
On February 3, 1972, Mendenhall passed away after a bout with cancer. She had dedicated more than eighteen years of service to the students of East Carolina. On January 17, 1974, the Board of Trustees honored her memory by dedicating the college union building as the Mendenhall Student Center.