An "Aszer Blady" was not found, but with the search "fuzzy" for the first name, there were four possibilities, and this was the only one who's birth year would fit the school demographics.
Uszer Blady (Sr, presumably) was born in 1907, making it possible for him to be a father at the age of 22 to Uszer Blady. They both have the same Limanow 100 address, said to have died in Lodz ghetto on 12/06/1943.
The person selected to be his mother was born in 1900, making her 29 when she had him, also noting the surname difference to "Blada". She matches both address locations on Limanow and Reiterstrasse.
The person presumed to be the younger sister was born in 1933, 4 years after Uszer. She also shares both addresses. She has a deportation date of 12/09/1942, which means she was sent to Chelmno.