Hicks earned a Bachelor of Science degree from Boston University in 1952, and a JD from Boston University Law School in 1955. Hicks stated that her father's death in 1950 left her resolved to follow in his footsteps. At this time female law students were still rare; Hicks was one of only nine women in her class of 232. Hicks formed close friendships with two other female students, one Jewish and one black, and she studied for exams with a group made up of mostly minorities. Hicks was admitted to the bar and practiced law with her brother John as the firm of Hicks and Day.