Harp, the president’s 35-year-old executive assistant, has come under increased scrutiny since The Washington Post reported last month that she was just one of a handful of close staffers who accompanied the president on a catering truck that transported him to a secret plane to depart Turkey. The president also gave $45,000 to Margo Martin, a 31-year-old communications adviser who films his daily activities for social media, and Chamberlain Harris, a 26-year-old White House aide who was appointed to the Commission of Fine Arts, which has oversight of the president’s ballroom and other Washington-area construction projects.