By Gabe Friedman/(JTA) — It isn’t up for debate — Katie Ledecky is currently the best female swimmer on the planet. The 19-year-old from Bethesda, Maryland, who won a gold medal in the 2012 London Olympics at age 15, has never lost a final of a major international race. Now she has a good chance of taking home 5 medals from the Rio Olympics, and she might break some world records along the way (she has already broken multiple ones during her short career).

How is someone under the age of 20 poised to enter the discussion of best-ever female swimmers? Part of Ledecky’s inspiration, as revealed in a Sports Illustrated profile in June, comes from the story of her Jewish grandmother, Berta, 83. Berta, who is Czech, is the mother of Ledecky’s father. Berta and her non-Jewish husband Jaromir (who went by Jerry), met in the United States in 1956, about eight years after Jerry had immigrated from Prague with only five dollars in his pocket. Berta — whom writer S.L. Price describes as a “formidable” woman — once spent a year working as a translator for Albert Einstein at the Polytechnic Institute of Brooklyn.

When Katie was 10, Berta took her to a Jewish cemetery in Prague and showed her graves of her family members who died during the Holocaust. Price doesn’t mention the exact number Berta’s family lost during World War II, or provide details of Berta’s experiences during the Holocaust, but the memory clearly stuck with Katie. Although Ledecky is Catholic and famously recites the Hail Mary before her races, Price writes that the “fuel” that drives Ledecky includes the visit to “a Jewish cemetery in Prague.”

CAP: Katie Ledecky