Her name was Mary. And as much as she loved her baby, she gave birth to him at a time when many unwed mothers, especially those without means, could not keep their children.

So in the early 1930s, she entrusted her infant into the arms of caregivers at the hospital on a hill in Dorchester, where he was cared for, loved, and nurtured. Eventually, mother and son would reunite. But as the boy grew into a man — a military veteran and then a beloved teacher — he never forgot the warm kindness he received at the hospital.

And that explains why, weeks after Robert Cosmos died in October at age 83, St. Mary’s Center for Women and Children received a check from his estate for $20,000.

“They took care of him there until his mother could take care of him,’’ said Barbara Ayers, Mr. Cosmos’s first cousin and the executrix of his will. “He was very private, and he didn’t mention it to many people, but what a wonderful job they did. And they’re still doing it.’’

Yes, they are.

Perhaps Mr. Cosmos knew full well that the love he received in 1932 remains in blossom today at the former hospital on a hill, a place where tonight little children will sleep in cozy rooms as Boston’s glass-and-chrome skyline twinkles in the dark a few miles and a lifetime away.

“We have little ones here, and for the first time in their lives, they feel loved and nurtured and safe,’’ Deirdre Houtmeyers told me Monday as we walked along the center’s corridors. “They can go to bed at night knowing that no one’s going to hurt them.’’

Houtmeyers, a Boston College graduate and the daughter of a Newton carpenter, spent her career as the director of the addictions program at St. Elizabeth’s Medical Center and she now leads St. Mary’s with a passion that is palpable.

“I believe if you can help, you must help,’’ she told me, her eyes watering as we greeted the women whom her staff of about 100 are helping to nurture and guide just as Robert Cosmos was helped 80 years ago. “This is the perfect opportunity for me to help these families along their journey to self-sufficiency.’’

What a journey that is. Little kids who suffered from unspeakable abuse. Learning disabled and homeless women working toward high school equivalency degrees. Family shelters that provide safe harbor from domestic violence.

“I call it home because I trust the staff,’’ 20-year-old Yanira, homeless and pregnant at age 15, told me. “It’s not just a place where you sleep; you’re surrounded by people who really love you.’’

You can feel that love in this place. It’s there in the brightly decorated doors of its clients. It’s there in the smiles and the verve of the staff. And it’s there in the eyes of the little kids who will receive presents from neighborhood firefighters on Christmas morning. The tree will shine brightly. There will be a festive holiday meal. But, caregivers know, amid the smiles and expressions of wonder, there will be, too, some tears and anxiety. This holiday, for even the littlest ones, is not always a gauzy Hallmark commercial.

The center has an $8 million budget, $1.2 million of which has to be raised privately, and Houtmeyers makes sure nothing is squandered. “Money is not wasted here,’’ she said.

She is surrounded by women — on her staff and among her clients — who depend on that careful stewardship.

Christians from around the world, dressed in their holiday finest, will stream into churches on Christmas Day. There will be soaring music, angelic choirs, and glad tidings of great joy. There will be bright candles on the altar and wreaths made of pine branches wrapped in ribbon.

It’s a holy moment, a moment of magic and of hope.

Amid the splendor, it’s important to remember that there was a woman at the center of it all in that Bethlehem manger more than 2,000 years ago.

She did all the work. Her name was Mary.

Thomas Farragher is a Globe columnist. He can be reached at thomas.farragher@globe.com.