On an uncommonly warm spring night, 25 women with but one thing in common gathered in a Main Line home and soon filled it with happy chatter. Their potluck feast stretched across kitchen counters laden with pastas and salads, bottles of wine, and platters of cheese. They sipped, and nibbled, and laughed, more than they had once thought possible.

Membership in this sisterhood was nothing that any of them wanted, or even imagined. All had lost children, the worst loss possible. Here, each smile was hard-won.

Patricia Robbins' twin daughters, Charlotte and Vanessa, died of cystic fibrosis at 24 and 25.

Joan Garbutt's son Todd was 37 when he took an accidental overdose of prescription drugs.

Nancy Winkler's daughter, Anne Bryan, 24, was among the six killed in the collapse of the Salvation Army store in Center City in June 2013.

Lisa Baurley's 5-month-old son, Ryan, was suffocated by a babysitter.

Mary Jane Hurley Brant's 28-year-old daughter, Katie, succumbed to the brain tumor she had fought for 10 years.

A psychotherapist from Newtown Square, Brant started Mothers Finding Meaning Again in 2009. She wanted to create a community in which women like her could find comfort, make peace with their loss, and redefine themselves in the absence of a child.

"Their lives have been so shattered," said Brant, 69, "they forget who they were and who they are."

She focused on mothers, she said, because they grieve differently than fathers, who often keep their sorrow to themselves. Women grasp the curative power of sharing.

No two stories are alike.

For Winkler, former Philadelphia city treasurer and now a partner in a financial-management firm, tragedy hit with shocking suddenness. "We didn't have any advance warning," she said of her daughter's death in the infamous tumbled-down store. Others "have to suffer watching their child be ill."

Yet, she said, a "powerful common thread" transcends circumstances and unites the women.

Convening monthly, they talk about not only the tragedies that brought them together but also jobs, illnesses, divorces, anniversaries, remaining children, grandchildren.

"I'm not here for Todd anymore," Garbutt, 79, the group's president, said at last month's meeting. "I'm here for all of you."

A Berwyn homemaker who reared six children, she called her son Todd in Florida in early 2008. When he didn't answer, she asked someone to check on him. He was fine. Still, she couldn't shake the feeling that he wasn't. Two days later, she and her husband drove to Delray Beach, arriving at his townhouse Feb. 2. Todd had been dead seven hours.

Garbutt walked into her first Mothers meeting 2½ years later.

She was too upset to tell her story, but listening was enough.

"I walked out and it was raining," she recalled. "I remember looking up to the sky, and letting the rain fall on my face and saying, 'God, I found a place where somebody understands.' "

Mothers for whom the grief is freshest see the women who have endured it the longest and understand that there's hope, Brant said.

In the beginning, they often disconnect, quit jobs, seek solitude, take refuge at a summer beach house or even on the sofa. Garbutt remembers being sapped of the will to do little but sit in her den.

With the grief can come overwhelming guilt.

"It's this visceral understanding that you carried this child in your body and you feel that somehow you failed," said Melonie Moultrie, 60, whose son died of a drug overdose in 2014. "You had a job to keep your kid alive."

Lisa Baurley's mommy-friends vanished after her infant son died in 1992.

"They thought, 'Your baby died, mine will die,' " as if he had had a contagious disease, said Baurley, 50, of King of Prussia.

An autopsy found signs of shaken baby syndrome, she said, but Ryan's death was ruled sudden infant death syndrome. She and her husband, Michael, believed he had been murdered.

The couple pursued their own investigation for a time, but after they had two more children, the Baurleys decided to put it to rest and focus on their son and daughter.

Twenty years later, police got a tip that led to the conviction of a babysitter, who is serving a 10- to 20-year sentence for third-degree murder.

During the Mothers meeting, Baurley, a nurse who joined the group in 2010, briefly rested her head on the shoulder of Jo-Anne Harris.

In August 2009, Harris' 20-year-old son, Brandon F. Thompson, was stabbed to death by a former girlfriend's ex-boyfriend.

"April 10 was his birthday," she said, "and I've been reliving the night he died."

Harris described her life immediately after his death as a kind of robotic functionality. The former university administrator underwent therapy and moved out of the townhouse that she had planned to share with her son. She attended the mothers' meetings, stopped for a while, and then returned.

The "cloud" that rendered her unable to smile has begun to dissipate, she said. "You learn that you will be able to get up in the morning."

For Patricia Robbins, a year passed before she could even feel "a little bit of joy," she said.

Her twins had been diagnosed at 9 months with cystic fibrosis, a genetic disease that causes the buildup of thick mucus that progressively restricts breathing.

Charlotte Robbins-Sylvester died at 24 in November 1999, followed four months later by Vanessa Robbins-Burke, 25.

"I knew that if I stayed in that sadness, [my daughters] would be so upset," said Robbins, now 64.

She quit her job as vice president of development at Chester County Hospital, and wrote a book about her experience, In the Morning Light. She takes comfort in what she believes are signs of her daughters' presence, like the bluebirds they loved.

Other women have found their voice. Brant wrote When Every Day Matters: A Mother's Memoir on Love, Loss and Life. Some have started foundations and scholarship funds in memory of their children. Fran Gerstein, a therapist who teaches at Philadelphia University, began to write poetry.

Gerstein's 28-year-old son, Daniel, died of an accidental drug overdose in February 2014. Her experience with Mothers Finding Meaning Again inspired her to start another support group, one for parents whose children died of substance abuse.

That kind of death comes with a "certain stigma," Gerstein said, "and the idea that people think maybe you weren't a good parent."

She and her husband, Stuart, hosted the Mothers Finding Meaning Again meeting in March, a celebration of the group's seventh anniversary.

Yes, celebration.

"My husband was like, 'Why is everyone laughing and yelling their heads off?' " Fran Gerstein said. "He was expecting a lot of crying. We are a strong group of women, and you can feel that."

After dinner, they sat in a circle in the living room. The conversation ranged from the challenge of Mother's Day to the difficulty of attending weddings and baby showers, knowing your child will not experience any more of life's joyous moments.

At the end, the mothers stood and held hands for their monthly ritual: Each stated her name, the name of her son or daughter, and how long her child has been gone.

Suzanne Schoenhut said her son's name, Joe. He had died at 35 of alcohol poisoning.

He has been gone nine years, and Schoenhut, 68, has finally gotten to the other side of the grieving process, she said later.

"I know I'm there because just recently I've been able to calmly mention that I have a son who passed away," she said. "Before, I couldn't bring myself to say it. Now I can."