This is not exactly unexpected. I hope it was productive:

Hillary Rodham Clinton held a private, one-on-one meeting with Senator Elizabeth Warren in December at Mrs. Clinton’s Washington home, a move by the Democrats’ leading contender in 2016 to cultivate the increasingly influential senator and leader of the party’s economic populist movement.

The two met at Whitehaven, the Clintons’ Northwest Washington home, without aides and at Mrs. Clinton’s invitation.

Mrs. Clinton solicited policy ideas and suggestions from Ms. Warren, according to a Democrat briefed on the meeting, who called it “cordial and productive.” Mrs. Clinton, who has been seeking advice from a range of scholars, advocates and officials, did not ask Ms. Warren to consider endorsing her likely presidential candidacy. Aides to Mrs. Clinton did not immediately respond to requests for comment, and aides to Ms. Warren could not be reached.

The conversation occurred at a moment when Ms. Warren’s clout has become increasingly evident. After the November election, Senator Harry Reid, the Democratic leader, appointed Ms. Warren, a Massachusetts freshman, to a leadership role in the Senate; she led a high-profile effort to strip a spending bill of rules sought by large banks; and a patchwork of liberal groups began a movement to draft her into the presidential race.

Ms. Warren has repeatedly said she is not running for president, and she has taken no steps that would indicate otherwise. Still, she is intent on pushing a robust populist agenda, and her confidants have suggested that she will use her Senate perch during the 2016 campaign to nudge Mrs. Clinton to embrace her major causes: addressing income inequality and curtailing the power of large financial institutions.

The get-together represented a step toward relationship-building for two women who do not know each other well. And for Mrs. Clinton, it was a signal that she would prefer Ms. Warren’s counsel delivered in person, as a friendly insider, rather than on national television or in opinion articles. And for Ms. Warren, the meeting offered the opportunity to make clear what she believes are the most pressing national issues.

That Mrs. Clinton — who is currently developing her economic platform — reached out to Ms. Warren suggests that she is aware of how much the debate over economic issues has shifted even during the relatively short time she was away from domestic politics while serving as secretary of state.

Mrs. Clinton was often criticized by the right as a doctrinaire liberal during her husband’s presidency and, as a presidential candidate, ultimately ran as more of an economic populist than Mr. Obama did. But she is now seen by some on the left as insufficiently tough on Wall Street. That perception, denounced by allies as an unfair criticism, has stuck in part because of her husband’s policies, and because of the lucrative speaking fees she has collected from financial firms and private equity groups since she left the State Department in early 2013.

The meeting in December fell two months after a more awkward encounter: Mrs. Clinton and Ms. Warren crossed paths at a Massachusetts rally for the Democratic nominee for governor there last year, Martha Coakley. At that event, Mrs. Clinton repeatedly described Ms. Warren as a champion against special interests and big banks; Ms. Warren, in turn, barely acknowledged Mrs. Clinton, who was the featured guest, in her remarks.