She said she was confident that Clinton and Obama would be able to unite the party and cited the "enormous amount of graciousness" in Clinton's concession speech as proof.
"I think if we keep that feeling going, I think we have a great capacity. And I think if it's going to happen, I think it will happen before the convention," she said.
Obama has tried to make a public show of his respect for Clinton.
In Detroit recently, some of his supporters in the crowd booed when Clinton's name was mentioned. Obama interrupted his speech to scold the heckler, saying, "You up there! Senator Clinton is one of the finest public servants we have in American life today."
But late last week, during a session with the Congressional Black Caucus, it was apparent how sensitive Clinton's backers still are to any apparent slight.
When a member of the caucus asked Obama to reach out Clinton's female supporters, Obama said he would try to soothe any raw emotions, but he also suggested that the conservative positions on women's issues held by Sen. John McCain, the presumptive GOP nominee, might help Clinton supporters "get over it."
Those three little words — "get over it" — angered some of Clinton's backers, showing just how delicate a Democratic truce may be.
Rep. Diane Watson, D-Calif., a longtime Clinton supporter, found Obama's words were dismissive, off-putting.
"Don't use that terminology," Watson told Obama.
But another former Clinton backer, Rep Yvette Clarke, D-N.Y., did not react the same way.
"I, personally, as a Hillary supporter, did not take that as something distasteful," Clarke said. "Nothing like that."
But, Clarke said, Watson "latched on to those three words."
ABC's Jennifer Duck contributed to this report.