Supreme Court Justice Ruth Bader Ginsburg speaks to the Northern Virginia Technology Council. (Jacquelyn Martin/AP)

Lawyers who argued before the U.S. Supreme Court would sometimes confuse Justice Sandra Day O’Connor for Justice Ruth Bader Ginsburg, the two first women to preside on the nation’s high court, Ginsburg said Tuesday.

“Every year Sandra and I served together, someone would call me Justice O’Connor because they heard a woman’s voice,” she said at a breakfast this morning hosted by the Northern Virginia Technology Council, at which she was keynote speaker.

Today, with three women on the court—Elena Kagan and Sonia Sotomayor in addition to Ginsburg—that doesn’t happen anymore, she said.

“No one calls me Justice Sotomayor and no one calls Justice Kagan Justice Ginsberg,” she said. “It’s an exhilarating change. It’s wonderful for schoolchildren who come though to see women are there.”

The first sign that women were there to stay, she said, was when the court renovated the justices’ robing room after her arrival to add a women’s restroom. Previously, there was only a men’s restroom and O’Connor, the first female justice, had to return to her chambers to change.

Ginsburg observed a “transformation” in the late 60s and 70s when she was an attorney —when her daughter went to school, working moms were relatively rare in her neighborhood but by the time her son was in school 10 years later, it was much more common, she said.

Ginsburg spoke at the Hyatt Regency in Reston, and the event was moderated by Ted Olson, a partner at Gibson Dunn and former solicitor general under George W. Bush.

Ginsburg often drew laughs from the crowd with measured but relaxed humor. When asked about her relationship with Justice Antonin Scalia, she read aloud lyrics from an opera score “Scalia/Ginsburg” that poked fun at their conflicting interpretations of the Constitution.

When asked about retirement, she said justices should stay “as long as she can do the job full steam. Can you think and write with the same fluency? At my age, you take it year by year. I’m OK this year.”