The honor of delivering the first reading at Pope Francis’ funeral Mass on Saturday fell to Kielce Gussie, an American who works as a reporter with Vatican News.

It was, she said on social media, “a great way to say goodbye” to the pontiff.

In a strong, resonant voice before the many thousands of mourners who had gathered in St. Peter’s Square in Vatican City, Ms. Gussie read from the Acts of the Apostles 10: 34-43, a Bible verse that Francis chose for the service and that holds large significance for Catholics.

Ms. Gussie, 28, grew up in Florida, and graduated from Mount St. Mary’s University in Maryland with a degree in theology, according to her LinkedIn profile. She began working in Rome in 2019, according to her profile, and last October joined Vatican News — a news agency that Francis created to bolster news coverage of the church and the Vatican.

“I’m really happy to be here because it’s a great way to say goodbye to Pope Francis,” Ms. Gussie said on social media outside St. Peter’s Basilica on Saturday morning before the Mass. She added that her last memory of Francis was from her birthday. “He gave me a little blessing,” she said. “It’s really a special way to spend my birthday.”

She said it had been difficult to see Francis grow frail in his final days, “but he gave everything until the end.”