The museum has only one letter between Mary-Amy Cross and her cousin, Norman Rockwell, said Stephanie Plunkett, chief curator at the Norman Rockwell Museum, but the diaries and family stories show him mentoring his younger cousin and her responding to his work with her developing and independent eye.
On one weekend visit, Plunkett said, Rockwell showed her a painting for a Post cover of a girl looking over a train seat at a G.I. and his sweetheart.
He asked what she thought, and she admired it. Later, when his wife asked her the same question, she admitted that the brightly colored train seats distracted her from the people, and when pressed she told him. Those train seats are now a deep, quiet blue.
In that one letter, Rockwell praised Cross for her experimentation and persistence.
The world they shared stayed with her life-long, decades after she left New York and her job illustrating greeting cards andbooks from Harvey, the seven-foot rabbit, to a repair guide called "Mr. Hobbes Can Fix it."
After her children were born, she had a studio in the dining room. Her second son, Peter Cross, said she would clear up just enough to fit in Thanksgiving dinner.
Whenever she traveled, she would bring her water color kit -- to Europe, Glacier Bay in Alaska, Arizona canyon country. Cross found a hand-drawn map in one of her books from a trip across country, flagged with her thoughts and drawings to record happenings along the way "like a train hitting a cow."
On family vacations, Cross said, his father would take him and his two brothers hiking at Acadia or Mount Desert Island, and his mother would paint. They would return from an all-day hike to find that she had finished two water colors in the time.
"She said a good watercolor should take an hour," Cross said. "More than that will muddy it up. Get it, get it right, or start a new one."