When Karen Frostig was a child in the 1950s and ‘60s, passport photos of her paternal grandparents hung on the wall of her house in Waltham. Frostig’s father, as a young Jewish man, had fled Vienna in 1938 and ultimately landed in Cuba. In late 1941, his parents were deported to Jungfernhof , the first Nazi concentration camp in Latvia. They died there, probably within months. “Those photos were hanging in our living room in silence for my whole life, and I walked by them every day,” Frostig said in a recent Zoom interview with the Globe from her home...