A second independent source, the discovery of the daughter Miriam Sefer, and the boundary of the bloodline
Geni is the second verification channel among the four bloodline channels. Its importance: it corroborates the lineage from a source separate from AZR's own writings, contributed the discovery of the daughter Miriam Sefer, and stops at the same boundary as the other channels — which strengthens the conclusion that the boundary is the edge of the documentation, not an accidental gap.
1 · What Geni Corroborates
Item
Status on Geni
The paternal line (Tsvi-Hirsh)
corroborated
The maternal line (the Brook family)
corroborated
The daughter Miriam Sefer
discovered through Geni
The undocumented link (Brook→Golda)
stops here, like the other channels
2 · The Discovery of the Daughter Miriam Sefer
Geni's unique contribution to the database: the discovery of the daughter Miriam Pfeffer/Sefer, who did not appear in the primary sources surveyed at first. This completed the list of descendants: Yemima Taubkin (1891–1980), Miriam Pfeffer (1892–1966), Michael (1896–1967), Yehuda Ben-Azar (1900–1986), and Binyamin Azar (1910–1981). Note: the Wikipedia entry records "Miriam Pfeffer" (not "Sefer").
3 · The Boundary of the Bloodline: Cumulative Corroboration
The Same Boundary, from an Independent Source
Geni stops at exactly the same place as AZR's writings, Tidhar, and JewishGen: Tsvi-Hirsh on the father's side, and the missing link between R. Alexander Ziskind Brook and Golda on the mother's side. When a second, independent source stops at the same boundary, the boundary is strengthened as a finding.
4 · A Contradiction Originating in Geni
Date of Death and Governorate
Geni contributes to two open contradictions in the database: the date of death (Geni: 25 Elul / 3.9.1945, versus Wikipedia/Tidhar: 28 Elul / 6.9.1945), and the governorate of Lyady (Geni: Vitebsk, versus Wikipedia/Tidhar: Mogilev). The governorate contradiction has been resolved: Lyady lay in Mogilev Governorate until World War I and passed to the Vitebsk region afterwards, so Geni recorded the later period. The date-of-death contradiction remains open.
5 · Geni's Standing as a Source
A fair distinction: Geni is a crowd-sourced platform, part of whose content is derived from AZR's own writings. It is therefore not entirely independent of the first channel. Nevertheless, its cross-checking against Tidhar and against the 1875 record, which are independent of it, is what gives the bloodline its strength.