[2][3][4] Lewis worked as a law clerk to South Carolina Circuit Court Judge Owens Taylor Cobb, Jr. from 1984 to 1985.

From 1985 to 2012 she worked at Lewis & Babcock, LLP, starting as an associate in 1985 and becoming a partner in 1987.

[3][4] Representative Jim Clyburn recommended Lewis to fill a judicial vacancy on the United States District Court for the District of South Carolina that was created by the elevation of Judge Henry F. Floyd to the United States Court of Appeals for the Fourth Circuit.

[5] On March 16, 2011, President Barack Obama formally nominated Lewis to the District of South Carolina.

On March 8, 2012, the Judiciary Committee reported her nomination to the floor of the Senate by an 11–6 vote.