STOCKBRIDGE -- A mermaid reclines on lawn. A figure leans bare head and shoulders on the side of a hot tub -- made out of snow.

In a quiet street north of Boston, a young mother turned wet snow into sculpture.

Not long before, she had worked as an illustrator in New York. Among days of sketching in museums and nights of dancing on roller skates, she wrote to her brother in the army. In May 7, 1945, she "went nuts looking for a radio," to listen to the announcement of peace. It was V-E Day, and she wanted to make sure her family and friends overseas were safe. She drew herself in pen, a short-haired girl looking dazed with elation and relief.

She kept a diary in pictures, in free-hand pen sketches.

(Courtesy of Norman Rockwell Museum)
And on the weekends, it showed her taking the train to Arlington, Vt., to visit her cousin and his family and show him her portfolio.

Her cousin's museum how has her diaries on display, surrounded by water colors from the Brooklyn pier to the New Hampshire lakes.

Mary-Amy Cross has a posthumous show of paintings, mixed media, sketches and illustrations at the Norman Rockwell Museum, around the corner from his painting of her as a child.

"She was artistic from when she was very young -- she always knew what she wanted to do," said her son, Peter Cross, also an artist and photographer. "Her dad owned an ice company in Providence, R.I., around the time when refridgeration came in, and he lost he business. So Norman paid for her art school. Norman's mother had also lived with them."

Mary-Amy Cross went to Pratt, where her diary shows her working late at her drawing board, sharing sundaes with friends, taking the subway to hear her cousin speak in the city, and talking with him in his studio about her studies.

"Rockwell enjoyed knowing what younger people were doing," said Stephanie Plunkett, chief curator at the museum, "and she worked hard. In the diaries, there's a repeated pose of her at her drawing table, and she's sweating. One thing I love in her work -- she, like Rockwell, wouldn't want to do anything else. After her children were born, she gave up her job, but she always painted."

"She had that lifelong dedication at her core. For many artists it is integral, though they may not receive recognition. She was painting completely for herself."

"To us, it was always what she did," Peter cross said. "It was always there. The house always had her art hanging on the walls," acrylics, pen and ink, painted rocks, watercolors.

"She was independent, especially for the age she grew up in," he said.

She went canoeing into her 80s. And to live in New York and work as an illustrator in the 1940s, he said, took determination.

(Mary-Amy Cross / Courtesy of Norman Rockwell Museum)

"She seemed fearless," Plunkett said.

She too went to Pratt, and she enjoyed following her fellow alum's adventures in her diaries, through the same foundation classes: two- and three-dimensional art, figure drawing, art history.

Cross remembered his mother's sculpture and the birthday and Christmas cards she drew, the birthday cakes in the shapes of castles and hot rods.

"She wouldn't just do the normal thing," he said.

She saw brightness and humor and brought them out. Once, at Lake Winnipesaukee, Cross said, the family camped on Three-mile Island in five straight days of rain, and she painted the lake and the islands in the mist. He thinks it is one of her best paintings.

She liked to paint from life, he said. "She said unless you reach a certain level, you should work from what's in front of you" -- that it was important to be there within touch of the reality.

Plunkett admired her confidence, a red truck giving a touch of color on the horizon line beside yellow barns and a sunlit shallow stream.

"She puts [color] down without worrying about it, and things feel believable," she said.

Cross remembered her last painting.

His mother died in October, 2010. In the spring of that year, he photographed a stone bridge over a nearby river, and they both painted the scene from the prints.

"She put me to shame," he said, "with her skill and deftness and technique."

She had always encouraged him in his artwork, he said. "It's funny to think what she would have thought of this show. She would have been humble and yet proud. The show as a whole fits together."

If you go ...

What: 'All in the Rockwell family: The art of Mary-Amy Cross'

Where: Norman Rockwell Museum, route 183, Stockbridge

When: Through Sunday, Weekdays 10 am. to 4 p.m. and weekends 10 a.m. to 5 p.m.

Admission: $16 for adults, $14.50 for seniors, $10 for students, $5 for children 18 and under, and free for children 5 and under

Information: www.nrm.org