WASHINGTON — The American economy is doing well enough that senators largely ignored the subject as they questioned Janet L. Yellen, the Federal Reserve chairwoman, for two hours on Thursday morning.

Instead, her appearance before the Senate Banking Committee was devoted mostly to regulatory issues.

Republicans sought Ms. Yellen’s support for proposals to loosen or eliminate some strictures imposed on financial institutions after the 2008 financial crisis. Democrats pressed her to affirm the importance of those regulations.

Ms. Yellen, who has played a crucial role in rebuilding the regulations, made it clear that she was proud of her work.

“I believe we have done a great deal since the financial crisis to strengthen the financial system and to make it more resilient,” she told the committee. Asked whether some of the rollbacks proposed by the Trump administration and congressional Republicans might increase the chances of a new crisis, she said, “Some of them, yes.”

At the same time, Ms. Yellen was carefully conciliatory, repeatedly agreeing that some rules might be too strict, and expressing a general willingness to consider changes. She also reiterated her support for reducing the regulation of community banks, a popular idea among members of both parties, though specifics are hard to come by.

Ms. Yellen said little about monetary policy, the stated purpose of the biannual hearing. The Fed raised its benchmark interest rate in June for the third consecutive quarter, and it plans to begin reducing its bond holdings this year.

Ms. Yellen said the economy remained in good health. “I don’t see anything inherent in the nature of the expansion that suggests it will come to an end anytime soon,” she said.

Appearing before a House committee on Wednesday, Ms. Yellen said that the Fed was paying close…