As a teacher, writer and lecturer, Muehlberger has been telling the stories of how more than 20,000 Jewish refugees found a home in Shanghai. It is important to keep telling them, because "new Nazis are emerging, and it is necessary to stand up to them," she said during an online conference with the media in Shanghai.

In 2014, when the wall was first established in the museum, there were more than 13,000 names, and in 2020, when the museum was refurbished and the wall rebuilt, the names had increased to 18,578, Chen says. The number keeps growing, Muehlberger explained, "because we still have information coming in from all over the world".

Her parents Hermann and Ilse Krips met each other in Frankfurt. In 1938, Hermann Krips was sent to the Dachau concentration camp for four weeks, until Ilse got him released by obtaining exit papers. In March 1939, they boarded one of the last ships to take refugees to Shanghai, arriving in the city in April. Sonja was born six months later.

All through the rest of his life, her father "never forgot how people were reduced to numbers in the camp," said Muehlberger. "He believed people should be named."

She showed her birth certificate, on which she was identified as "Baby Krips". Her father went to the German Consulate General in Shanghai, to get her passport. Hermann was well aware of the threat posed by the Nazi government, but he was determined to get a passport for the baby girl, Muehlberger said. Three months after he went to the Shanghai Municipal Council and registered the baby girl's name Sonja, after Sonja Henie, a three-time Olympic gold medal-winning figure skater and film star from Norway.