Isabella I of Castile

As a Catholic monarch, Isabella I's Jewish identity score is, perhaps unsurprisingly, a perfect zero. Her reign was marked by fervent religious devotion, which included the establishment of the Spanish Inquisition and the infamous Alhambra Decree of 1492, expelling all Jews from Spain. Any Jew who didn't convert was out, and those who converted were still under the suspicious eye of Torquemada. So, not exactly a "friend of the tribe" on that front.

Regarding her origins, there's no credible evidence to suggest any Jewish ancestry for Isabella. Her lineage is firmly rooted in the Castilian royal houses, meticulously documented through centuries of intermarriage among European nobility. While some might claim a crypto-Jew in every prominent historical family, Isabella’s family tree is about as gentile as they come.

For kvell-worthiness, Isabella scores a modest one. While funding Columbus's voyage to the New World was a monumental achievement, leading to centuries of colonization and discovery, it's somewhat overshadowed by the simultaneous expulsion of the Jews from Spain. Discovering America is great and all, but ethnically cleansing a kingdom? Not so much. It's hard to kvell when the "Great Discoverer" was sent off by a "Great Expeller."