In the very old records, the wife / mother's surname does not appear. Later this reversed! and as Jewish marriages were not legally recognised in the civic society, unless they registered the marriage with the civic authorities (non-Jewish at the time), the only parent that was certain was the mother, so her name often was given to the baby...but later when the child grew up, they may have taken up the father's surname, or both.
Esther's parents / surname is not known. She may not have had a Germanic (enforced) surname, as she was born in the period when it was still ongoing (not wholly enforced).
Jacob Goldsand appears on records on JRI-Poland / Jewishgen.org as a 'witness' to the birth of the baby. If you search under 'Goldsand' Tarnow you will see that he (and another Goldsand, Samuel) appear as witness on multiple baby records. Likely he was assigned to witness births, as a legal/religious duty.
