Anna Altenberg-Burshtain (born Anna Altenberg) was the daughter of Necha (Markowicz) and Bernard (Berek) Altenberg, both of whom immigrated to Belgium from Tomaszów Mazowiecki and Kałuszyn, Poland in the interwar period. Anna was born in 1932 in Antwerp, where her father was a photographer and the owner of a large photo studio called Bernard Studios. He was also the inventor of the first electric copier, which he displayed at the 1930 World's Fair. Anna had three sisters: Rebecca (b. 1931), Frederica (Frieda, b. 1936) and Micheline (Mieneke, b. 1939).
After receiving an order to Aryanize his business, Bernard sold his studio to a non-Jewish friend, Mr. Lontie, who returned it after the war. In June 1942 when the large scale round-ups of Jews began, the Altenbergs decided to go into hiding. The four girls were placed with a non-Jewish family, while Bernard and Necha hid separately and moved frequently to avoid capture. Their last hiding place was with the Van Gaal family. While in hiding Bernard assisted the Belgian resistance by drawing stamps for false papers. After the four girls had been in hiding for a few months, their rescuers, fearing arrest, sent the girls back to their parents. Lacking other alternatives, Bernard and Necha placed the girls in the Jewish orphanage in Antwerp that was run by the AJB (Association des Juifs de Belgique), the official Jewish administration. In November 1943, the orphanage was forced to relocate to Lasne. Immediately after the liberation, Bernard and Necha retrieved their daughters. Though all of their immediate relatives survived the war, many of their extended family perished, including Bernard's brother, Shmuel Altenberg, two sisters, Raszka Altenberg-Zebrachi and Feige Altenberg-Szafir, and their families.