Question: Who is Prince Boris Of Leiningen's paternal grandmother?
Sentence (from "Prince Karl of Leiningen"): Prince Karl Vladimir Ernst Heinrich of Leiningen (2 January 1928 – 28 September 1990) was the younger son of Karl, 6th Prince of Leiningen (1898–1946) and Grand Duchess Maria Kirillovna of Russia.
Relevant evidence: Yes