Sykes was born in Portsmouth, Virginia and raised in the Washington, D.C., area. Her mother, Marion Louise (née Peoples), worked as a banker, and her father, Harry Ellsworth Sykes, was a US Army colonel employed at the Pentagon.[5] Sykes attended Arundel High School[6] in Gambrills, Maryland, and went on to graduate from Hampton University[6] where she earned a bachelor’s degree in marketing and was a member of Alpha Kappa Alpha. After college, her first job was as a contracting specialist at the National Security Agency (NSA),[6][7] where she worked for five years.[8]
Sykes' family history was researched for an episode of the 2012 PBS genealogy program Finding Your Roots With Henry Louis Gates Jr. Her ancestry was traced back to a 1683 court case involving her paternal ninth great-grandmother Elizabeth Banks, a free white woman and indentured servant, who gave birth to a biracial child, Mary Banks, fathered by a slave, who inherited her mother's free status. According to historian Ira Berlin, a specialist in the history of American slavery, the Sykes family history is "... the only such case that I know of in which it is possible to trace a black family rooted in freedom from the late 17th century to the present."[9]