By Justin Sink
Hillary Clinton now serves as secretary of State.
Singiser is the latest in a string of women at the White House to announce their departures. Melody Barnes, the president's domestic policy adviser, announced earlier this month plans to leave at the end of the year, while deputy communications director Jen Psaki, who had been with the president since his time as a senator in Illinois, said in September that she was joining a consulting group. Communications director Anita Dunn and energy and environmental adviser Carol Browner have also departed within the past year.