When she was 12, Debra Todd walked a few blocks to a neighbor’s house in Ellwood City. He was a lawyer in town who needed help filing legal papers, and for some reason young Debra had been suggested for the job.

As she sorted papers for 50 cents an hour, the lawyer, James Keller, would tell her about his cases. He was thrilled when she reorganized one set of documents from alphabetical order to stages of litigation. At one point, Mr. Keller and his wife and office manager, Beverly, told her she could be a lawyer someday herself.

“Literally, I said, ‘Oh, can women become lawyers?’” she recalled. “I never knew many lawyers at all and the television lawyer I knew was Perry Mason.”

“It was like a light went off,” she added. “I decided at 12, ‘This is it. I’ve found what I love and this is what I want to do.’ I never changed my mind.”

On Friday, the eager young file clerk from Lawrence County will be formally installed as the first female chief justice in the 300-year history of Pennsylvania’s Supreme Court.