Sanders leaves her job under a considerable shadow.
Grisham, a single mother of two boys, is one of the longest-serving members of the Trump administration, and began as a campaign aide in 2015. She holds a great reputation in both the East and West Wings, which made her the odds-on favorite to replace Sanders among White House insiders.
A source close to the Trump administration told the Daily Wire "Grisham is pure Trump", adding "she holds down the East Wing easily and has no loyalties to any faction within the Republican Party".
Sanders, who will leave the White House on Friday, also tweeted out her support for Grisham. Grisham did not respond to a request for comment from Newsweek last week on rumors she would take Sanders's job, or Tuesday after she was named. She won't talk to us anymore, ' he quipped, praising his exiting press secretary.
President Trump delays planned mass deportations
Neither Ms Pelosi nor senator Chuck Schumer, the top Democrat in the Senate, had an immediate comment on the delay. Since the June 7 agreement, Mexican troops have deployed on the country's borders and arrested more migrants.
Grisham also handled press for then-Attorney General Tom Horne when a former staffer alleged that Horne and his senior aides essentially ran his 2014 re-election campaign out of his official office while paid by taxpayers.
'Whomever he decides to go with, it's a very public face and gives voice to the administration and to the public, ' the person noted.
Once part of the campaign, Grisham wrangled media as Trump canvassed the country. "There aren't a lot of people who have a lot of regular interaction with both of them".
Sanders recently told a group of reporters that she does not regret ending the daily briefings in the James A. Brady Briefing Room, and declined to say what was her toughest day on the job. She'll be returning to the state after a family vacation.
"Mrs. Trump's life story is an inspiration to millions of mothers and female entrepreneurs, and to me personally", she said.
"I've always found it sad that a group of women spend so much time attacking another woman, whose only goal is to help children", she said.