Ms. Westerhout’s abrupt and unexpected departure came after Mr. Trump learned on Thursday that she had indiscreetly shared details about his family and the Oval Office operations she was part of at a recent off-the-record dinner with reporters staying at hotels near Bedminster, N.J., during the president’s working vacation, according to one of the people, speaking on the condition of anonymity to discuss White House personnel issues…

Ms. Westerhout, a former Republican National Committee aide who also worked for Mitt Romney’s 2012 presidential campaign, reportedly cried on election night because she was upset over Mr. Trump’s victory. As such, the president at first viewed her warily, as a late convert to his cause who could not be trusted.