Question: What is the date of death of Prince Christian Of Schaumburg-Lippe (1898–1974)'s mother?
Sentence (from "Prince Christian of Schaumburg-Lippe (1898–1974)"): Prince Christian of Schaumburg-Lippe (20 February 1898 – 13 July 1974) was a German prince and head of the Náchod branch of the princely house of Schaumburg-Lippe.
Relevant evidence: No