Merin wiped away tears as the Silver Star was pinned to her lapel during a short ceremony attended by friends and family at her home in Westlake Village. The other medals were presented on a plaque.
"It just confirms what a great man he was," Merin said. "He gave up his life for our country and our freedom."
Merin's mother, Celia, married Markel in 1941 when he already was in the military. They had met at a Jewish temple in Buffalo, N.Y.
About four months ago, the manager of a West Hollywood apartment building where Merin's mother lived in the 1960s found a box containing papers and the Purple Heart while cleaning out lockers in the laundry room, Merin said.
The manager contacted Purple Hearts Reunited, a nonprofit that returns lost or stolen medals to vets or their families. A search led to Merin.
She became "kind of emotional, because I don't have a lot of pictures, I don't have a lot of stories, and I've always been a crier," she said.
Markel was killed in the last days of World War II on May 3, 1945, in Italy's Po Valley while fighting German troops as an officer with the 88th Division of the 351st Infantry Regiment, said Zachariah Fike, the Vermont Army National Guard captain who founded Purple Hearts Reunited.
"The accounts suggest that he was out on patrol and he got ambushed and he charged ahead and basically took out a machine gun position to save the rest of his guys," said Fike, whose organization has returned about two dozen medals.
Markel was awarded the Purple Heart and Silver Star posthumously.
Merin's mother never talked in detail to her daughter about Markel. "It was a very difficult topic for her. When my father died, she was seven months pregnant with me," Merin said.
Merin's mother was told about the discovery of the Purple Heart but didn't live to see it - she died Feb. 1 at age 94.