She moved to Dallas, Texas in 1922 with her husband, George Ernest Hughes, whom she had met in law school. Her husband quickly found employment after law school, but Sarah faced significant obstacles as a woman during a time in which law firms generally did not regard women as qualified. Eventually, the small firm of Priest, Herndon, and Ledbetter gave her a rent-free space and even referred some cases to her in exchange for her services as a receptionist. As her practice grew and became more successful, she became increasingly active in local women's organizations. She joined the Zonta Club, the Business and Professional Women's Club, the Dallas Women's Political League, the League of Women Voters, YWCA, Dallas College Club, and the American Association of University Women. Hughes served as Chair of the AAUW Committee on the Economic and Legal Status of Women, advocating equal pay jury service for women, and improved status and recognition for women in the Armed Services. She practiced law for eight years in Dallas before becoming involved in politics, first being elected in 1930 to three terms in the Texas House of Representatives as a Democrat. In 1935, Hughes accepted an appointment as a state judge from Governor James V. Allred for the Fourteenth District Court in Dallas, becoming the state's first female district judge. In 1936 she was elected to the same post. She was re-elected six more times and remained in that post until 1961.