Ruemmler has already delayed her departure by a year, Politico reported Wednesday.
She planned a move to New York in late 2012 and had found housing but agreed to stay on at President Barack Obama's request.
"It makes sense," a source in the administration told The Washington Post. "She's been at the White House counsel's office for three years, and started with the administration at the beginning, in 2009."
The administration has quietly begun looking for someone to replace her, Politico said.
Ruemmler became Obama's White House lawyer in June 2011 after serving as deputy to her predecessor, Bob Bauer.
Her office has framed newspaper story on the wall with the headline "Guilty," a souvenir from her days in the Department of Justice when she was a lead federal prosecutor in the trial of Enron executives Ken Lay and Jeff Skilling.