Let’s face it: If you’re a fan of Ruth Bader Ginsburg — I think she walks on water — the first thing you want to know when you see her in person is, How is she doing?

Bird-like to begin with, the 81-year-old Supreme Court justice has looked even frailer in recent years, alarming those who love her for her mind and her passionate dissents on the divided bench.

So after seeing her Sunday night at the 92nd Street Y, I can report that, well, she looked great. Tiny and bowed for sure (it’s quite possible that she actually can walk on water), she seemed fit and spry in a sleek black pants suit and sheer gloves. Sitting between moderator Nina Totenberg of NPR and Dorit Beinisch, the former president of Israel’s Supreme Court, Ginsburg was sharp and witty.

No, she doesn’t waste words — or at least, she saves them for dissents like the one she issued Saturday (apparently after an all-nighter) calling Texas’s voter I.D. law “purposely discriminatory.” And while much of the evening’s attention was directed at her, she elegantly steered the conversation to Beinisch with pointed questions about Israel’s judicial system, its treatment of women, and its relations with the military.

Totenberg quickly got to the question on many minds in the Upper East Side audience: Will she consider retiring soon to allow President Obama to appoint her successor? Said Ginsburg: “To those who make that suggestion I ask a question, and that question is this: Who do you think our president can nominate and get through today’s Senate? In life, it is always, ‘What is the alternative?’ If anyone could get through, it would not be someone who has my record.”

Totenberg reminded Ginsburg that if the next president is Republican, he might appoint someone “quite alien” to her positions. “I’m very hopeful about 2016,” said the justice, which brought riotous applause and appreciative laughter.

By design, the evening brought plenty of reminders of the progress being made — and work still to be done — in women’s rights in both countries. Beinisch, Israel’s first woman state attorney and the first woman to head the High Court, described her role in such cases. In 2012, for instance, Beinisch shifted the burden from the employee to the employer in equal pay cases, so that women need show only that there is a significant difference in salaries, without having to prove discrimination.

The two Jewish jurists swapped tales of the obstacles they had to overcome as women in a male-dominated field, but you could almost see Ginsburg’s temperature rise as she remembered the slights she faced as a woman lawyer. She told of the school principal who kept calling her in for conferences about her “lively” son — assuming that her husband, and not she, was too busy to be bothered. She almost seemed to regret her quiescence in her earliest jobs. “The first woman doesn’t want to be seen as a troublemaker, doesn’t want to rock the boat,” she said.

But there was no holding back when she discussed Safford Unified School District v. Redding, the 2009 case in which a 13-year-old Arizona girl was strip-searched by school officials who suspected she might be hiding ibuprofen in her underwear. The males on the court seemed to engage in what Ginsburg called “fun and games” as they compared what happened to the girl to their own experiences in locker rooms. Ginsburg reminded her colleagues that a 13-year-old girl is sensitive about her body, and there is nothing benign about a strip search at that age. “When I said this, from the bench, it stopped,” said Ginsburg. Only Clarence Thomas dissented when the court ruled that the girl’s constitutional rights were violated.

Supreme Court justices tend not to tell tales out of court, although Totenberg said she keeps trying to get Ginsburg to “make news.” So in addition to enjoying some clear and concise discussion of past cases, I listened for the anecdotes that humanized Ginsburg and her colleagues.

At one point Ginsburg asked Beinisch if she was familiar with Adalah, a group, sometimes controversial, that argues for Arab minority rights in Israel. (“Of course,” said Beinisch.) I braced for some insight into Ginsburg’s views on the topic, but instead she explained her personal connection: She officiated at the wedding of Adalah’s cofounders, Hassan Jabareen and Rina Rosenberg. Jabareen was a student of Ginsburg’s at American University.

But it turns out Ginsburg did make news, after all. At one point, Totenberg asked the justice about the “Notorious RBG” T-shirt, which salutes Ginsburg in the style of the late rapper Biggie Smalls, aka “The Notorious B.I.G.” (At six feet, three inches and 380 pounds, B.I.G. was about four and half RBGs.)

Ginsburg, as it turns out, has “quite a large supply,” she explained, to the delight of the blogosphere. “I think a law clerk told me about this Tumblr and also explained to me what Notorious RBG was a parody on. And now my grandchildren love it, and I try to keep abreast of the latest that’s on the Tumblr.”

So there you have it. Ruth Bader Ginsburg is looking fit and acting sharp. She remains passionate about ending discrimination.

And she not only collects “Notorious RBG” T-shirts, but she keeps abreast of stuff on Tumblr.

That makes one of us.