Who is the White Houses social secretary?

The United States Cabinet (usually referred to as the President's Cabinet or simplified as the Cabinet) is composed of the most senior appointed officers of the executive branch of the federal government of the United States.

No, the Social Secretary is part of the President's personal staff.

See the related links for a complete list of the cabinet and the cabinet level staff.

http://en.wikipedia.org/wiki/United_States_Cabinet#Cabinet