Reddick graduated from Hunter College High School in New York City in 1969 and received a BA in history and literature from New York University (1973) and a master's degree in International Affairs from Columbia University’s School of International Affairs (1975).

After completing her graduate studies, Reddick worked for several years at the Africa-America Institute in New York and Washington.

Reddick began her Foreign Service career in 1980 and was assigned in 1981 as consular officer to the Harare Embassy, Zimbabwe.

From 1997 to 2000, she was the chief of the political section at the Taipei Main Office of American Institute in Taiwan (AIT).

Following those posts, she was appointed by President George W. Bush and sworn in as United States Ambassador to Gabon and São Tomé and Príncipe.