[1] Her legal career began in 1981 when she served as an attorney for a single trial while employed at Brown, Compton, and Prewett Ltd in El Dorado, Arkansas.

[1] From 1981 until 1984, Hickey worked as a staff attorney at Murphy Oil Corporation.

[2][3] On April 6, 2011, President Barack Obama nominated Hickey to a seat on the United States District Court for the Western District of Arkansas to fill the vacancy created when Harry F. Barnes assumed senior status in 2008.

[4] On October 13, 2011, the United States Senate confirmed Hickey by an 83–8 vote.

[3] She became chief judge on February 14, 2019, succeeding Paul K. Holmes III.