Gender: boy
Has to be born from 1921-1927 because we know he went to Gymnasium, which was highschool. He was born between those dates: 1925, which fits the criteria.
Henryk Wajsbergs ghetto address: Goldschm 25 19
and Moltke 9
Moszek Wajsberg must be his father because they have similar addresses and the date of the fathers birth fits the criteria for him to be his child. It also says the father was born June 23, 1897 and it says he died June 10th 1943.
Chawa Wajsberg must his mother because they have similar addresses and the date of the mothers birth fits the criteria for him to be her child. It also says the mother was born in 1892 and it also says that her occupation was a Beamt.
Stela Wajsberg must be Henryk Wajsberg's sister. She has the same address as him and his parents and her birthdate is August 25, 1928. So they were very close in age.