She has spent countless hours in the cozy basement gym that will now bear her name. And, she has accumulated many precious memories in her nearly half-century at the school.
There was the school's appearance at the Palestra in 1973, when Biello said, "about 1,400 to 1,500 Hallahan fans came out to cheer" them on.
There was Pope John Paul II's visit to Philadelphia, in which the Center City school served as headquarters for the Mass he said on the Ben Franklin Parkway.
And, she said, there were the many traditions at the school such as, "our beautiful Christmas Mass liturgy at the Cathedral, and our girls jumping in Love Park fountain [on the final day of school].''
But Biello was hard-pressed to pick out a single "best" memory, because, she said, "every day at Hallahan was a great day."
"I never considered being at Hallahan a job," Biello said. "Every day was a happy day. It was wonderful.
"I can't believe it went by so quickly. I was 21 when I was hired on March 4, 1963. The administration, faculty, students and staff have all been so good to me. I love my Hallahan family."
The feeling is mutual.
"Our school's theme this year is "Hallahan, Faith's Brightest Beam," school president Sandra R. Young said. "It's a phrase from our alma mater. And, I truly believe that Pat Biello is one of Hallahan's brightest beams."