She will appear before the committee for a second day on Wednesday.
Tuesday also marked the first of two challenging confirmation hearings for Xavier Becerra, the attorney general of California and Mr. Biden’s nominee for secretary of health and human services.
In contentious questioning, Republican members of the Senate Health, Education, Labor and Pensions Committee sought to portray Mr. Becerra, who has little experience in public health, as unqualified, while painting his positions on abortion and health care as radical.
Mr. Becerra, who will lead an extensive coronavirus vaccination effort if confirmed, said he sought to focus on the country’s most immediate challenges stemming from the pandemic and find opportunities to compromise on more politicized health policies.
“When I come to these issues, I understand that we may not always agree on where to go,” he said, “but I think we can find some common ground.”
Mr. Becerra will face another round of questioning from the Senate Finance Committee on Wednesday.
On Tuesday, the Finance Committee also convened a confirmation hearing for Adewale O. Adeyemo, Mr. Biden’s pick to serve as deputy Treasury secretary.
The steady beat of hearings helped make up for lost time for senators who spent six days this month focused entirely on former President Donald J. Trump’s impeachment trial.
It also cleared the way for senators to consider even more nominees this week. On Wednesday, senators will take up William J. Burns’s nomination to lead the Central Intelligence Agency, and on Thursday they will turn to Katherine C. Tai’s nomination to serve as the United States trade representative.