Supreme Court Justice Ruth Bader Ginsburg appears at an event organized by the Museum of the City of New York in December. (Rebecca Gibian/AP)

Justice Ruth Bader Ginsburg returned to the Supreme Court Friday for the first time since she underwent surgery in December, a court spokeswoman said.

Ginsburg, 85, participated in a private conference with her colleagues as they considered which cases to accept for review or reject, said court spokeswoman Kathleen Arberg.

One item on the agenda was whether the court should skip its normal procedures and consider whether the Trump administration may add a question about citizenship to the 2020 Census form sent to every household in the country.

The court will meet in public on Tuesday for oral arguments, and Ginsburg’s return to the court on Friday makes it likely she will be on the bench then.

Ginsburg missed January arguments after undergoing a pulmonary lobectomy Dec. 21 to remove two malignant nodules from her left lung. It was the first time the justice had missed oral arguments since she joined the court in 1993, even though she has had two bouts with cancer in that time.

After the December surgery, Ginsburg worked from home reviewing briefings and arguments in the January cases, and Chief Justice John G. Roberts Jr. said she would participate in deciding them. She has also been a part of previous private conferences, and voted last week when the court granted an emergency order blocking implementation of a restrictive Louisiana abortion law.

Conspiracy theories about Ginsburg have proliferated on fringe right-wing social media, with some demanding to see “proof of life.”

Ginsburg attended a concert about her life sponsored by the National Constitution Center on Feb. 4, but those suspicious about her said they did not believe media reports about her appearance.