Haley Thompson grew up Catholic in Ridley Park, but the Rosemont College sophomore had met only one nun before enrolling at the school founded by the Sisters of the Holy Child Jesus.

Once an abounding presence in ministry, nuns had receded from the forefront. Thompson figured that the women who gave up the chance at marriage and motherhood did little but go to church, pray, and "eat in between."

Then she met Sister Helen McDonald.

The 76-year-old nun taught school in North Philadelphia, studied Spanish in Puerto Rico, worked as a legislative aide in Congress, and supervised religious communities in California and Rome. She lived in a cute Havertown apartment, not a convent.

Thompson, 20, got a reality check, a one-on-one connection with religious life through a national program meant to demystify a sacred choice and preserve the history of what may become a vanishing sisterhood.

She and McDonald are part of SisterStory, a three-year-old initiative that pairs students and nuns to create an oral archive of the experiences of women who have given all for God. Students meet regularly with nuns to interview them; those reflections are recorded and uploaded to the project website, www.sisterstory.org.

So far, SisterStory has paired 165 nuns with 185 students at about 20 colleges and universities, including Rosemont and Immaculata University, both on the Main Line.

Some subjects have pursued missions that gave them a national spotlight, among them Sister Helen Prejean, the anti-death-penalty activist portrayed by Susan Sarandon in Dead Man Walking, and Sister Carol Keehan, the Catholic Health Association CEO who worked with President Obama to pass the Affordable Care Act.

Most of the sisters, though, have tales seldom told, of boyfriends left behind, of parents who were joyful, or crushed, by their decision. They speak movingly of vows of celibacy, poverty and obedience.

Project leaders at the two Roman Catholic schools that are home base for SisterStory - Alverno College in Milwaukee and St. Catherine University in Minneapolis - hope that, in the interview process, nuns and students forge lasting relationships.

"Quite often, [students'] only exposure [to nuns] is through the movie Sister Act," said Molly Hazelton, an adjunct professor at St. Catherine and director of SisterStory. "There's also a stereotype that sisters are mean. We are debunking those myths."

Since 1965, the ranks of Catholic nuns in the United States have dwindled from 181,000 to 47,100, a nearly 74 percent decrease, according to the Center for Applied Research in the Apostolate, which is affiliated with Georgetown University.

About 90 percent of nuns are older than 60.

The declining numbers and increasing age have forced religious communities to reorganize, sell convents, expand retirement and nursing care, and increasingly rely on laypeople to carry out ministries that were once largely their province.

With fewer on the front lines, the truth about religious life can get lost.

Students at Rosemont College and Immaculata say they thought of the typical nun as wearing a long habit, and enforcing discipline with iron fists.

Nuns, while viewed as an "appendage to the church," have been, instead, an integral part, said Sister Rose Marie DeCarlo, 80, a SisterStory subject and retired general superior of the Sisters, Servants of the Immaculate Heart of Mary.

The religious community founded 2,850-student Immaculata in 1920. About 36 nuns are active on campus, down from about 60 three decades ago. At 1,100-student Rosemont, founded in 1921, two nuns work on campus; in the 1970s, there were 68.

Eight nuns and nine students at Rosemont have participated since interviews started in fall 2015. The school plans to use the model for an oral history project that will be added to the curriculum. At Immaculata, six nuns and six students were matched for the project in spring 2015, and the university is considering continuing its involvement next year.

Funding for SisterStory initially came from a $3.3 million grant given by the Conrad N. Hilton Foundation to St. Catherine University in 2013. The award has supported National Catholic Sisters Week and other initiatives, such as SisterStory, that aim to raise awareness of nuns and their ministry - with a supplementary goal that the projects might help increase the number of people taking up the vocation.

The schools are given video cameras, audio recorders, and boom mics. Students blog on the SisterStory website and transcribe their sessions. Video is edited and uploaded to the site by project staff. Though initially students were paid a modest stipend, the program is moving toward a policy of providing college credit.

The sisters "need to be heard," said Kyah Hawkins, 21, a Rosemont junior. "They are dying off, and if no one writes the stories down, no one will be able to learn from their past."

Hawkins interviewed Sister Jeanne Marie Hatch, 80, Rosemont's vice president for mission and ministry. The pair bonded over the loss of their fathers, and a story Hatch shared about the night before she took final vows.

"My brother came to see me with his new baby boy, and I held him. I started to cry because I realized I would never be a mother or have my own family," the nun said. "It was a very hard night."

But Hatch said she also thought that she was called to the ministry, and she would always have a family in her religious community.

Sister Jane Roach, 88, a retired principal, signed up for SisterStory in part because she wanted to get to know young people who could tell her how college life differs from her student days, when she was deciding to enter the sisterhood.

She was interviewed by Sabrina Heggan, a Rosemont sophomore, who asked Roach whether she would hit the redo button, given the opportunity.

"I was surprised when she said 'No,' " Heggan said.

Her life has been so rewarding, Hatch explained, that she would have no reason to change it.

Katelyn Starr, 21, an Immaculata senior who interviewed DeCarlo, grew up Catholic, but in a family with little involvement in the church. She has been so affected by her interaction with nuns on campus, she said, that she recently was baptized and confirmed in the religion.

Hatch has an even more ambitious wish for the SisterStory interviewers.

Maybe, just maybe, some student will be intrigued enough to consider a religious vocation.

"All adults are searching for a way to be of service," Hatch said. "I pray they'll look this way."