Lucy Wiese, 7, seen in the pediatric unit of the NIH Clinical Center, has a rare genetic disorder and weak immune system. But that didn’t prohibit her from playing in the blizzard’s snow, with an assist from a nurse. (Jan Wiese)

Lucy Wiese was walking around inside the National Institutes of Health Clinical Center on Saturday looking out the windows and watching the snow fall.

She was wearing her purple knit cap, purple winter coat and polka-dot pants. She and her mother, Jan, paused at one point to look at the playground outside, covered in snow.

Maybe they could go out and brush off the swings, she said to her mother.

Lucy, 7, is a huge fan of the movie “Frozen.” And the doctors had thought she might be able to go out for a bit.

But the weather was awful, and Lucy's health, in the wake of her bone marrow transplant six weeks ago, was still fragile. The trip outside was called off.

Lucy Wiese shows off her snowball. (Courtesy of Jan Wiese)

Clinical research nurse Alex Classen, 26, of Rockville, however, had been thinking about the weather and the sick kids in the center. She brainstormed. If the children couldn’t go out in the snow, maybe she could bring it to them.

Clad only in her scrubs, Classen dashed into the blizzard several times Saturday and scooped up basins of snow for Lucy and the other children.

So about midday, Lucy, who has been in the hospital since November, stood in her room before a poster of Elsa, “Frozen’s” Snow Queen, and made a small snowman.

As the big storm moved away, and people across the region struggled with the aftermath, Jan Wiese said: “It’s been a special weekend, for sure.”

In a telephone interview from NIH, after the story was reported by CBS, Jan Wiese said her daughter suffers from Job syndrome, a rare disorder in which a person’s immune system functions poorly.

As a result, Lucy has suffered recurring bouts of pneumonia and other dangerous respiratory problems most of her life, her mother said.

During one illness, Lucy was put into a medically induced coma for several weeks to help her lungs heal. She has spent time in isolation and has often been room-bound. Her mother home-schools her.

Last spring, after other treatments had fallen short, doctors suggested a bone marrow transplant.

Her mother was the donor. The operation was Dec. 11. Marrow was withdrawn from her mother’s hip and pelvis and given to Lucy through a tube in her chest.

Things were going well until late December, when Lucy developed a fungal pneumonia in her lungs. But she rallied and has improved dramatically. “She’s like a different kid than she was a few weeks ago,” her mother said.

The family lives in Richmond. Lucy’s father, Scott, is a doctor, and a native of Reston. She has a little brother, Joel, 5.

The weekend snowstorm was the biggest in Lucy’s memory, her mother said.

“Before the storm, her doctors had talked about, maybe she could go outside a little bit in the snow,” Jan Wiese said. Lucy got up and put on her winter garb.

“But it was really coming down pretty hard and it was windy, and I thought . . . maybe we should wait,” her mother said. “She was a good sport.”

Then Classen stepped in.

“We have a bunch of patients who are really sick and can’t necessarily go out and play in the snow like normal kids,” she said. “So I thought it would be fun for them to be able to touch and play and experience the snow.”

“I had the idea in the morning,” she said. She cleared it with everybody, grabbed some basins and made several dashes out into the blizzard, wearing only black-and-pink scrubs.

She scooped the snow with the basin and ran back inside. She filled six basins.

“I got blasted with . . . snow,” she said.

As for the children, “they just had so much fun,” she said.

“Anything I can do to make these kids smile is awesome,” she said. “So whenever they’re happy, it just makes my day.”