COTTONWOOD, Idaho -- For weeks after coming to the convent, Sister Petronilla Lieser dreamed every night about the young beau and marriage plans she left behind.

Now 83, she still recalls boarding the train in Minnesota at age 18, leaving her childhood home for the Monastery of St. Gertrude in north-central Idaho.

"I thought I should be a nun so I said, 'I'm going to stick it out if it kills me,' and it hasn't killed me yet, has it?" she asked, flashing a wide smile.

Like Sister Lieser, many of the nuns at St. Gertrude's are well past retirement age. And though most of the senior sisters entered Roman Catholic religious life in their late teens or early 20s, these days most new members are middle-age.

Mary Mendez is a postulant at the Benedictine monastery, trying to decide if she will take vows to become a nun. The former nurse was drawn to convent life at a later age, after she was divorced and her children were grown.

"I was a 53-year-old mother of three with a Benedictine heart and soul -- what a dilemma," Mendez said. "I just knew I wanted to do something meaningful with my life."

Mendez began to wonder about convent life after attending a spiritual retreat at a monastery in North Dakota.

"At first I thought perhaps if I went to another monastery and had a negative experience, that crazy notion would go out of my mind," she said.

But by 2001, Mendez had sold her California home and moved to Idaho. She volunteered at the Monastery of St. Gertrude for several months before finally beginning the process of becoming a nun.

She learned much about herself along the way.

"There were some interesting points," she said. "I remember the day I realized I didn't have any house keys and no phone number that was mine."

The abandonment of secular values such as independence and property ownership is part of the beauty of the Benedictine life, said Mendez.

"We're here to witness to the gospel's value. We're here to witness that there is more to life than a 401(k) and retirement home," she said.

Middle-aged sisters bring stability to the monastery, while seniors bring wisdom, said Sister Janet Barnard, the monastery's vocation director.

Young sisters are necessary because they bring the group energy and strength, Sister Barnard said. They are also rare. The youngest member of the monastery now is in her 40s.

"Society has changed and women have a lot more options," Sister Barnard said. "In the '40s and '50s, if women from this area thought at all about having a career, they went into religious life because otherwise they'd marry a farmer and be a farmer's wife."

Now, she said, it all depends on personal priorities.

"How do you know you're supposed to be a sister? That's just part of the mystery of God's plan. Who knows how God works?" she said. "I was a very idealistic person, and meeting the sisters gave me a group to be part of."

When Sister Barnard joined at age 23, the nuns would spend their summer evenings playing volleyball in the mountain shade. Now they're more likely to be sitting in lawn chairs, watching the sunset.

As the majority of sisters move toward retirement, the monastery's income is becoming a focus, Sister Barnard said.

"We've got one sister who's 101. How do we provide good care for them when medical costs are going up? We look for donors who believe in the work that we do, and we're looking more intentionally toward managing our forest land and developing our retreat program," she said.

Sister Barnard expects more recruits in the future.

"People often say, 'How can you make this choice? It's so hard.' Well, being married isn't easy either. I think for a lot of people, religious life hasn't been one of those choices presented," she said.

Now Sister Barnard talks to young Catholics at high schools and youth groups, and visits college campuses to invite young women to attend retreats at the monastery. She said that national religious groups -- such as the National Religious Vocation Conference in Chicago -- are spotting a trend with the young adults of Generation Y.

They are looking at making life commitments earlier and are more focused on serving than earlier generations, she said.

"There's a whole movement of wanting to be part of a religious organization that stands for something greater than themselves," said Sister Barnard.

For those who visit the monastery, stereotypes of austere living are scrubbed away. A large organic garden behind the four-story brick building supplies fresh produce for the women, and rich wooden moldings line the walls inside. A sunlit art studio holds half-finished paintings of church icons and down the hall a living area is decorated with Chinese prayer bowls and easy chairs.

There's a TV, a computer room, and an elegant chapel crowned by an elaborate silver, gold and oak altar.

The peaceful atmosphere is a draw to volunteers, who live and help out at the monastery.

"It's exciting for us to see that hunger for spirituality, whether they are called to become a sister or to associate with our community as a lay person," said development director Sister Mary Kay Henry. "We want to promote the volunteer experience, because it's very rich for us and very rich for them."

Sister Lieser has no concerns about the future of the monastery, and no regrets about her long-ago love.

"We are so very privileged. You can become a nun or a lay person, but the real thing is to do it full-heartedly. I made the vows of poverty, chastity and obedience," Sister Lieser said. "I praise the Lord for my vocation as a sister, because I just about got married. How much I would have missed out on then."