Ms. Kwon could not pay her rent. Her father was too poor to take her and her children in.

In 1978, she gave her youngest son to a childless family. She took her daughter and Song-hyuk, then 3, to a local orphanage that arranged adoptions. She saw her children playing with toys and other children, and left without saying goodbye for fear they would follow her.

“I know it sounds like an excuse, but I had no one to turn to for help,” Ms. Kwon said.

After giving her children away, Ms. Kwon worked in a plastics factory in Seoul. She kept a couple of black-and-white photos of her children. She would remember the days when she fetched water from the village well — spilling so much because of her leg that she had to make multiple trips — to give her babies a bath, or the times when they devoured what little food she could provide, usually rice mixed with soy sauce and cooking oil.

“I missed them, especially when it rained or snowed or when the sky was overcast,” she said. “But the belief that they were having a better life somewhere than I could ever provide has sustained me.”

Ms. Kwon later married a widower 20 years her senior. She said she had dedicated herself to caring for his two daughters as if they were her own, believing that she was doing what adoptive parents were doing for her own children. She also gave birth to four more daughters, now all in their 30s.

Her husband died years ago, and her grown children have moved away. She now lives in a low-slung house with another man, whom she married and who helped her raise her daughters. As she got older, she began using crutches or an electric wheelchair when traveling outside. In her room, when she moves, she drags a plastic chair to lean on for support.

Last year, Ms. Kwon got a call from a relative who remembered Song-hyuk and had watched the television documentary. In it, Mr. Crapser called out for his birth mother.