After helping engineer Donald Trump’s improbable and sweeping victory in the presidential race, Susie Wiles, the president-elect’s unassuming co-campaign chief, is seen as the frontrunner to become his White House chief of staff, according to six sources familiar with discussions inside the campaign.

The low-key Wiles, 67, will be the first woman to serve as White House chief of staff. “Susie is tough, smart, innovative, and is universally admired and respected," Trump said in a statement. "I have no doubt that she will make our country proud.”