She was just 17 when she met her future husband. She went on to guide his career and became an avid preservationist of vernacular architecture. Betsy Wyeth was the model for her husband’s 1966 painting “Maga’s Daughter.” Maga was a nickname for her mother. She played a major role in his career, saying, “It’s like I’m a director and I had the greatest actor in the world.” Betsy James Wyeth, the indomitable widow, collaborator and muse of the painter Andrew Wyeth, died on April 21 at her home in Chadds Ford, Pa. She was 98. She had been in declining...