When lo.oking for S. Hamermesz in the Lodz Ghetto Database, Sara is the only child that fits the school timeline for date of birth and gender. I elimintated every other S. Hamermesz that appears when you search for the inital S as the first name, the others are too old your too young.
I believe Mirjam is Sara's sister as they are only a couple years apart and they have the same residents. If they aren't sisters, they my be at least cousins as they share the same last name. I believe Szlama is her father as the timing fits since he would have been in his 30's when she was born and they have the same addresses in the ghetto.I also believe that Rajzla and Rajzla Zlata Hamermesz are related to her as they also share the same addresses. It is unclear whether one of them could be her mother as one would have been in her late 30's (Rajzla Zlata) and Rajzla in her late 40's when she was born. There is also someone named Zlata Rajzla (female) with the same first address also born in 1891 so it may be that there is an error and she is the same person as Rajzla Zlata and if that were true, it leads me to believe that Rajzla may be a mother or grandmothers name that is passed down in the family. The only other person with the last name Hamermesz is Schlama which is similar to the phonetic sounding of Szlama and this person is male and born in 1891 which leads me to blieve he is the same person I blieve to be her father, but I cannot be sure at this point in time.