"I've been praying," said Sister Ralph, a member of the Pennsylvania-based Sisters of the Blessed Sacrament for nearly three decades.
"I'm scared. So far, no one has asked me to move."
Moments later, a cathedral volunteer walked up -- shuffling papers in her hands -- and said, "I'm going to have to ask you to move. This section is for the clergy."
As the volunteer continued to the back of the vast cathedral, the nun said, "The sisters are all sitting on the side and we have the clergy here."
Francis, she said, would not approve.
Saturday's Mass was Pope Francis' first stop in Philadelphia
. He celebrated it before more than 2,000 -- mostly priests, "women religious" (as Catholic sisters and nuns are officially known) and deacons. In it, he invoked the name of Katharine Drexel,
who founded the Sisters of the Blessed Sacrament. He called her "one of the great saints raised up by this local Church."
Francis praised the "efforts of all those dedicated priests, religious and laity who for over two centuries have ministered to the spiritual needs of the poor, the immigrant, the sick and those in prison."
He spoke of "the hundreds of schools where religious brothers and sisters trained children to read and write, to love God and neighbor, and to contribute as good citizens to the life of American society."
For Sister Ralph, 55, and some other nuns, the Pope's praise for them collided with the slight they felt when it came to seating. After being moved from the center pews of the 150-year-old cathedral, Sister Ralph wiped tears from her eyes.
"I get emotional," she said as she awaited the pontiff. "That hurts. The religious have just as much honor as the clergy. If Pope Francis knew, he would say, 'No. Let her stay.'"
Sister Ralph had moved about 20 rows back but remained in the middle section, where she felt she would get a good view of the Pope. The volunteer stopped by with a reminder: She might have to move again.
Sister Ralph is director of religious education at the predominantly black St. Martin de Porres Church in North Philadelphia.
She knelt and prayed to "Mother Mary, Mother Katherine and my mother."
"I'm cool now," she said, as the basilica began to fill.
As the white-robed clergy filed into the sanctuary, another nun stepped out from the folding chairs set out for the religious on each side of the church. She, too, wiped tears from her eyes and told a group of reporters," Pope Francis would not like this."
Msgr. Joseph Gentili, pastor of Our Lady of Guadalupe Church in Doylestown -- about 30 miles north of Philadelphia -- sat in the front center row during the Mass.
He said the placement of the Catholic sisters and nuns in the cathedral was not a measure of their value. But he acknowledged that it was something Pope Francis "would not want."
But Gentili said the sisters and nuns are "highly regarded" in the five-county archdiocese as well as the church and that was reflected by Pope Francis' high praise for their dedication and work.
Months ago, the monsignor said, the Vatican closed an investigation of an umbrella group of American nuns.
In 2012, the Vatican accused the Leadership Conference of Women Religious, the country's largest group of Catholic nuns, of sponsoring "certain radical feminist themes incompatible with the Catholic faith."
American bishops were appointed to oversee the LCWR and the speakers invited to their conferences. That oversight abruptly ended in April.
A separate Vatican investigation encompassed all American "women religious" and sought to understand why their membership has dropped so deeply for decades. That investigation ended without any censure of the Catholic women, but some said they were deeply offended by its premise.
Sister Ralph said the words and actions of Pope Francis were bringing back people who had distanced themselves from the church.
"They're hearing his message," she said.
Her twin sister is a member of the Sisters of St. Joseph.
"I didn't want to be a nun," Sister Ralph said. "I thought, God, you got the wrong one. Even God must have gotten us confused."
But she attended a retreat one day and realized it was her calling.
"It was like the biggest burden had been lifted off my shoulders," she said. "I have been truly blessed. I have no regrets."
A couple of nights earlier in New York, Pope Francis expressed his "esteem and gratitude to the women religious of the United States."
And these words prompted applause:
"What would the Church be without you?"